diff --git a/app/api/extensions/arcim-migration/complete-invoice-lines/cron/__tests__/route.test.ts b/app/api/extensions/arcim-migration/complete-invoice-lines/cron/__tests__/route.test.ts
index 156b8c30..0813a694 100644
--- a/app/api/extensions/arcim-migration/complete-invoice-lines/cron/__tests__/route.test.ts
+++ b/app/api/extensions/arcim-migration/complete-invoice-lines/cron/__tests__/route.test.ts
@@ -50,7 +50,8 @@ const mockCount = vi.mocked(countRowlessInvoices)
 
 const EMPTY = {
   candidates: 0, providerInvoices: 0, matched: 0, unmatched: 0, completed: 0, headersUpdated: 0,
-  totalMismatch: 0, noLinesAtProvider: 0, rowsMismatch: 0, notHydrated: 0, vatUnresolved: 0, failed: 0, remaining: 0,
+  totalMismatch: 0, noLinesAtProvider: 0, rowsMismatch: 0, notHydrated: 0, vatUnresolved: 0, failed: 0,
+  historyAppended: 0, remaining: 0,
   hydration: { needed: 0, hydrated: 0, failed: 0, skippedForBudget: 0 }, dryRun: false,
 }
 
diff --git a/app/api/extensions/arcim-migration/complete-invoice-lines/cron/route.ts b/app/api/extensions/arcim-migration/complete-invoice-lines/cron/route.ts
index ff14a027..b17bbd96 100644
--- a/app/api/extensions/arcim-migration/complete-invoice-lines/cron/route.ts
+++ b/app/api/extensions/arcim-migration/complete-invoice-lines/cron/route.ts
@@ -159,6 +159,7 @@ export const GET = withCronContext('cron.arcim_migration_complete_invoice_lines'
     totalMismatch: 0,
     rowsMismatch: 0,
     failed: 0,
+    historyAppended: 0,
   }
 
   const completing = await ctx.forEach('register', registers, async ({ consent, candidates }, itemCtx) => {
@@ -188,6 +189,7 @@ export const GET = withCronContext('cron.arcim_migration_complete_invoice_lines'
     totals.totalMismatch += result.totalMismatch
     totals.rowsMismatch += result.rowsMismatch
     totals.failed += result.failed
+    totals.historyAppended += result.historyAppended
     itemCtx.log.info('migrated invoice rows completed for company', {
       companyId: consent.company_id,
       provider: consent.provider,
@@ -198,6 +200,8 @@ export const GET = withCronContext('cron.arcim_migration_complete_invoice_lines'
       notHydrated: result.notHydrated,
       totalMismatch: result.totalMismatch,
       rowsMismatch: result.rowsMismatch,
+      failed: result.failed,
+      historyAppended: result.historyAppended,
       hydration: result.hydration,
     })
   })
diff --git a/extensions/general/arcim-migration/__tests__/migration-registration-links.test.ts b/extensions/general/arcim-migration/__tests__/migration-registration-links.test.ts
index e13d1ce7..7e9dbd49 100644
--- a/extensions/general/arcim-migration/__tests__/migration-registration-links.test.ts
+++ b/extensions/general/arcim-migration/__tests__/migration-registration-links.test.ts
@@ -114,6 +114,7 @@ function baseOptions(overrides: Record<string, unknown> = {}) {
     companyId: 'company-1',
     userId: 'user-1',
     supabase: supabase as unknown as SupabaseClient,
+    createHistoryClient: async () => ({ from: vi.fn() }) as unknown as Pick<SupabaseClient, 'from'>,
     importCompanyInfo: false,
     importCustomers: false,
     importSuppliers: false,
diff --git a/extensions/general/arcim-migration/__tests__/migration-step-errors.test.ts b/extensions/general/arcim-migration/__tests__/migration-step-errors.test.ts
index 003418b2..5d2a4bff 100644
--- a/extensions/general/arcim-migration/__tests__/migration-step-errors.test.ts
+++ b/extensions/general/arcim-migration/__tests__/migration-step-errors.test.ts
@@ -84,6 +84,7 @@ function baseOptions(overrides: Record<string, unknown> = {}) {
     companyId: 'company-1',
     userId: 'user-1',
     supabase: {} as unknown as SupabaseClient,
+    createHistoryClient: async () => ({ from: vi.fn() }) as unknown as Pick<SupabaseClient, 'from'>,
     importCompanyInfo: false,
     importCustomers: false,
     importSuppliers: false,
diff --git a/extensions/general/arcim-migration/index.ts b/extensions/general/arcim-migration/index.ts
index 8e748401..15fe021d 100644
--- a/extensions/general/arcim-migration/index.ts
+++ b/extensions/general/arcim-migration/index.ts
@@ -1479,6 +1479,11 @@ export const arcimMigrationExtension: Extension = {
             companyId,
             userId: user.id,
             supabase,
+            // The behandlingshistorik rows the sales-invoice step writes need
+            // the service role (processing_history has no INSERT policy);
+            // built only when that step has rows to write.
+            createHistoryClient: async () =>
+              (await import('@/lib/supabase/server')).createServiceClient(),
             importCompanyInfo,
             importCustomers,
             importSuppliers,
diff --git a/extensions/general/arcim-migration/lib/__tests__/complete-invoice-lines.test.ts b/extensions/general/arcim-migration/lib/__tests__/complete-invoice-lines.test.ts
index 41b8379a..3c9b599c 100644
--- a/extensions/general/arcim-migration/lib/__tests__/complete-invoice-lines.test.ts
+++ b/extensions/general/arcim-migration/lib/__tests__/complete-invoice-lines.test.ts
@@ -10,9 +10,17 @@ import type { SalesInvoiceDto } from '@/lib/providers/dto'
  * when the provider's total agrees with the stored one, and leave anything it
  * could not reach for the next run rather than guessing. Every write goes
  * through the complete_invoice_rows RPC, one call per invoice, which is what
- * keeps two writers from doubling an invoice's rows.
+ * keeps two writers from doubling an invoice's rows, and every write that
+ * landed leaves one InvoiceRowsCompleted row in processing_history (#2312).
+ * The history append runs for real against the fake client, so the payload
+ * below is what the PII guard and the row shape actually accept.
  */
 
+vi.mock('@/lib/supabase/server', () => ({
+  createClient: vi.fn(),
+  createServiceClient: vi.fn(),
+}))
+
 vi.mock('@/lib/providers/resolve-consent', () => ({
   resolveConsent: vi.fn().mockResolvedValue({
     consent: { provider: 'fortnox' },
@@ -86,6 +94,7 @@ function storedRow(overrides: Record<string, unknown> = {}) {
     subtotal: 1250,
     vat_amount: 0,
     vat_rate: 25,
+    vat_treatment: 'standard_25',
     currency: 'SEK',
     exchange_rate: null,
     invoice_items: [],
@@ -175,6 +184,18 @@ function headerUpdates(calls: Call[]): Record<string, unknown>[] {
     .filter((h): h is Record<string, unknown> => h !== null)
 }
 
+/** The processing_history rows the run appended, in order. */
+function historyRows(calls: Call[]): Record<string, unknown>[] {
+  return calls
+    .filter((c) => c.table === 'processing_history' && c.method === 'insert')
+    .map((c) => c.args[0] as Record<string, unknown>)
+}
+
+/** Every call that touched a table other than the trail. */
+function tableWrites(calls: Call[]): Call[] {
+  return calls.filter((c) => c.method !== 'rpc' && c.table !== 'processing_history')
+}
+
 describe('completeMigratedInvoiceLines', () => {
   beforeEach(() => {
     vi.clearAllMocks()
@@ -193,6 +214,7 @@ describe('completeMigratedInvoiceLines', () => {
     expect(result).toMatchObject({
       candidates: 1, providerInvoices: 1, matched: 1, unmatched: 0,
       completed: 1, headersUpdated: 1, remaining: 0, totalMismatch: 0, notHydrated: 0, failed: 0,
+      historyAppended: 1,
     })
     // Only the matched subset is hydrated, so the budget is never spent on
     // invoices already complete on our side.
@@ -228,8 +250,30 @@ describe('completeMigratedInvoiceLines', () => {
     // Never the total, status or payments.
     expect(Object.keys(sent[0].p_header!)).not.toContain('total')
     expect(Object.keys(sent[0].p_header!)).not.toContain('status')
-    // Nothing is written outside the RPC.
-    expect(calls.filter((c) => c.method !== 'rpc')).toHaveLength(0)
+    // Nothing is written outside the RPC, except the trail.
+    expect(tableWrites(calls)).toHaveLength(0)
+
+    // One InvoiceRowsCompleted on the invoice: the writer, the provider,
+    // the consent, and the header split before and after (the pre-#1745
+    // 25 %-beside-0-kr shape replaced by what the detail form established).
+    const trail = historyRows(calls)
+    expect(trail).toHaveLength(1)
+    expect(trail[0]).toMatchObject({
+      company_id: 'co-1',
+      aggregate_type: 'Invoice',
+      aggregate_id: 'inv-1',
+      event_type: 'InvoiceRowsCompleted',
+      actor: { type: 'cron', id: 'complete-invoice-lines' },
+      payload: {
+        source: 'complete-invoice-lines',
+        provider: 'fortnox',
+        consent_id: 'c-1',
+        rows: 1,
+        header_updated: true,
+        header_before: { subtotal: 1250, vat_amount: 0, vat_rate: 25, vat_treatment: 'standard_25' },
+        header_after: { subtotal: 1000, vat_amount: 250, vat_rate: 25, vat_treatment: 'standard_25' },
+      },
+    })
   })
 
   it('writes the rows but leaves a header whose split is consistent (momsfri)', async () => {
@@ -241,10 +285,14 @@ describe('completeMigratedInvoiceLines', () => {
 
     const result = await completeMigratedInvoiceLines({ supabase, companyId: 'co-1', consentId: 'c-1' })
 
-    expect(result).toMatchObject({ completed: 1, headersUpdated: 0 })
+    expect(result).toMatchObject({ completed: 1, headersUpdated: 0, historyAppended: 1 })
     expect(insertedRows(calls)).toHaveLength(1)
     expect(writes(calls)[0].p_header).toBeNull()
     expect(headerUpdates(calls)).toHaveLength(0)
+    // The event says the header was left alone, and carries no split.
+    expect(historyRows(calls)[0]).toMatchObject({
+      payload: { rows: 1, header_updated: false, header_before: null, header_after: null },
+    })
   })
 
   it('fills a header whose rate is null (the post-#1745 "source did not say")', async () => {
@@ -390,9 +438,11 @@ describe('completeMigratedInvoiceLines', () => {
 
     const result = await completeMigratedInvoiceLines({ supabase, companyId: 'co-1', consentId: 'c-1' })
 
-    expect(result).toMatchObject({ completed: 0, headersUpdated: 0, failed: 0, remaining: 1 })
+    expect(result).toMatchObject({ completed: 0, headersUpdated: 0, failed: 0, remaining: 1, historyAppended: 0 })
     expect(writes(calls)).toHaveLength(1)
     expect(writes(calls)[0].p_header).not.toBeNull()
+    // Nothing changed, so nothing is recorded.
+    expect(historyRows(calls)).toHaveLength(0)
   })
 
   it('counts a refused or failed call as failed and goes on with the rest', async () => {
@@ -419,8 +469,46 @@ describe('completeMigratedInvoiceLines', () => {
 
     const result = await completeMigratedInvoiceLines({ supabase, companyId: 'co-1', consentId: 'c-1' })
 
-    expect(result).toMatchObject({ completed: 1, failed: 2, headersUpdated: 1, remaining: 2 })
+    expect(result).toMatchObject({ completed: 1, failed: 2, headersUpdated: 1, remaining: 2, historyAppended: 1 })
     expect(writes(calls).map((w) => w.p_invoice_id)).toEqual(['inv-1', 'inv-2', 'inv-3'])
+    // The trail names only the invoice whose write landed.
+    expect(historyRows(calls).map((r) => r.aggregate_id)).toEqual(['inv-1'])
+  })
+
+  it('threads one correlation id through every event of a run, attributed to the caller\'s actor', async () => {
+    mFetchAll.mockResolvedValue([storedRow(), storedRow({ id: 'inv-2', invoice_number: '1002' })])
+    const dtos = [providerInvoice(), providerInvoice({ id: '1002', invoiceNumber: '1002' })]
+    mList.mockResolvedValue(dtos)
+    mHydrate.mockResolvedValue(hydratedAll(dtos))
+    const { supabase, calls } = makeSupabase(() => ok)
+
+    const result = await completeMigratedInvoiceLines({
+      supabase, companyId: 'co-1', consentId: 'c-1', actor: { type: 'user', id: 'user-9' },
+    })
+
+    expect(result).toMatchObject({ completed: 2, historyAppended: 2 })
+    const trail = historyRows(calls)
+    expect(trail.map((r) => r.aggregate_id)).toEqual(['inv-1', 'inv-2'])
+    expect(trail[0].correlation_id).toMatch(/^[0-9a-f-]{36}$/)
+    expect(trail[1].correlation_id).toBe(trail[0].correlation_id)
+    expect(trail.every((r) => (r.actor as { id: string }).id === 'user-9')).toBe(true)
+  })
+
+  it('counts a write whose trail append failed as completed, not appended', async () => {
+    // The rows are committed by then; a missing change-log row is a logged
+    // gap, never a failed invoice the next run would find full.
+    mFetchAll.mockResolvedValue([storedRow()])
+    const dto = providerInvoice()
+    mList.mockResolvedValue([dto])
+    mHydrate.mockResolvedValue(hydratedAll([dto]))
+    const { supabase, calls } = makeSupabase((table) =>
+      table === 'processing_history' ? { data: null, error: { message: 'connection reset' } } : ok,
+    )
+
+    const result = await completeMigratedInvoiceLines({ supabase, companyId: 'co-1', consentId: 'c-1' })
+
+    expect(result).toMatchObject({ completed: 1, failed: 0, historyAppended: 0 })
+    expect(historyRows(calls)).toHaveLength(1)
   })
 
   it('dry run: reports the plan and writes nothing', async () => {
@@ -432,7 +520,7 @@ describe('completeMigratedInvoiceLines', () => {
 
     const result = await completeMigratedInvoiceLines({ supabase, companyId: 'co-1', consentId: 'c-1', dryRun: true })
 
-    expect(result).toMatchObject({ dryRun: true, completed: 1, headersUpdated: 1, remaining: 0 })
+    expect(result).toMatchObject({ dryRun: true, completed: 1, headersUpdated: 1, remaining: 0, historyAppended: 0 })
     expect(calls).toHaveLength(0)
   })
 
diff --git a/extensions/general/arcim-migration/lib/complete-invoice-lines.ts b/extensions/general/arcim-migration/lib/complete-invoice-lines.ts
index 1459a42e..c21775f1 100644
--- a/extensions/general/arcim-migration/lib/complete-invoice-lines.ts
+++ b/extensions/general/arcim-migration/lib/complete-invoice-lines.ts
@@ -35,11 +35,22 @@
  * locks the invoice, inserts the rows only when the invoice still has none
  * and applies the header split in the same transaction, so an invoice's rows
  * are written at most once whichever writer gets there first, and "rows
- * landed, header did not" is not a reachable state.
+ * landed, header did not" is not a reachable state. The call goes through
+ * completeInvoiceRows (lib/invoices/complete-invoice-rows.ts), which also
+ * writes the behandlingshistorik event for every invoice the RPC filled: one
+ * InvoiceRowsCompleted per invoice, with the header split before and after
+ * (BFL 5 kap 11 §, BFNAR 2013:2 p. 9.16). Every invoice a run completes
+ * shares one correlation id, so a run is one thread in the trail.
  */
 
 import type { SupabaseClient } from '@supabase/supabase-js'
+import type { ProcessingHistoryActor } from '@/types'
 import { ISO_DATE_RE } from '@/lib/invariants'
+import {
+  completeInvoiceRows,
+  type CompleteInvoiceRowsTrail,
+  type InvoiceHeaderVatSplit,
+} from '@/lib/invoices/complete-invoice-rows'
 import { createLogger } from '@/lib/logger'
 import { equalOre, roundOre } from '@/lib/money'
 import type { SalesInvoiceDto } from '@/lib/providers/dto'
@@ -55,6 +66,9 @@ import { mapSalesInvoice } from './entity-mapper'
 
 const log = createLogger('extensions/arcim-migration/complete-invoice-lines')
 
+/** The writer named in the trail; also the default actor id (the hourly cron). */
+export const COMPLETE_INVOICE_LINES_SOURCE = 'complete-invoice-lines'
+
 /**
  * How many invoices in this company the pass would try to complete: the
  * predicate `loadCandidates` uses (non-draft sales invoices with no rows),
@@ -87,6 +101,8 @@ export interface CompleteInvoiceLinesOptions {
   dryRun?: boolean
   /** Wall-clock ceiling for the provider detail fetches, in ms. */
   budgetMs?: number
+  /** Who the behandlingshistorik events are attributed to; the hourly cron when unset. */
+  actor?: ProcessingHistoryActor
 }
 
 export interface CompleteInvoiceLinesResult {
@@ -118,6 +134,8 @@ export interface CompleteInvoiceLinesResult {
   vatUnresolved: number
   /** Invoices whose write failed at the database. */
   failed: number
+  /** Of `completed`, those whose InvoiceRowsCompleted event landed in processing_history. */
+  historyAppended: number
   /** Candidates still without rows after this run: `candidates - completed`. */
   remaining: number
   hydration: HydrationReport
@@ -134,6 +152,7 @@ interface CandidateRow {
   subtotal: number | null
   vat_amount: number | null
   vat_rate: number | null
+  vat_treatment: string | null
   currency: string | null
   exchange_rate: number | null
   invoice_items: { id: string }[] | null
@@ -208,7 +227,7 @@ async function loadCandidates(supabase: SupabaseClient, companyId: string): Prom
     supabase
       .from('invoices')
       .select(
-        'id, user_id, customer_id, invoice_number, invoice_date, total, subtotal, vat_amount, vat_rate, currency, exchange_rate, invoice_items(id)',
+        'id, user_id, customer_id, invoice_number, invoice_date, total, subtotal, vat_amount, vat_rate, vat_treatment, currency, exchange_rate, invoice_items(id)',
       )
       .eq('company_id', companyId)
       .eq('document_type', 'invoice')
@@ -222,39 +241,21 @@ async function loadCandidates(supabase: SupabaseClient, companyId: string): Prom
   return rows.filter((row) => (row.invoice_items?.length ?? 0) === 0)
 }
 
-/**
- * The header VAT split the detail form established, as the RPC's p_header:
- * the six invoice columns it may rewrite, all present or none.
- */
-interface HeaderFill {
-  subtotal: number
-  subtotal_sek: number | null
-  vat_amount: number
-  vat_amount_sek: number | null
-  vat_rate: number | null
-  vat_treatment: string
-}
-
 interface PlannedWrite {
   row: CandidateRow
   /** The invoice_items columns per row; the RPC stamps invoice_id itself. */
   items: Record<string, unknown>[]
-  header: HeaderFill | null
-}
-
-/** What complete_invoice_rows returns (migration 20260906135730). */
-interface CompleteRowsOutcome {
-  ok: boolean
-  code?: string
-  wrote?: boolean
-  rows?: number
-  header_updated?: boolean
+  /** The header VAT split the detail form established, as the RPC's p_header. */
+  header: InvoiceHeaderVatSplit | null
 }
 
 export async function completeMigratedInvoiceLines(
   options: CompleteInvoiceLinesOptions,
 ): Promise<CompleteInvoiceLinesResult> {
-  const { supabase, companyId, consentId, dryRun = false, budgetMs } = options
+  const {
+    supabase, companyId, consentId, dryRun = false, budgetMs,
+    actor = { type: 'cron', id: COMPLETE_INVOICE_LINES_SOURCE },
+  } = options
 
   const result: CompleteInvoiceLinesResult = {
     candidates: 0,
@@ -269,6 +270,7 @@ export async function completeMigratedInvoiceLines(
     notHydrated: 0,
     vatUnresolved: 0,
     failed: 0,
+    historyAppended: 0,
     remaining: 0,
     hydration: { needed: 0, hydrated: 0, failed: 0, skippedForBudget: 0 },
     dryRun,
@@ -355,7 +357,7 @@ export async function completeMigratedInvoiceLines(
       }
     }
 
-    let header: HeaderFill | null = null
+    let header: InvoiceHeaderVatSplit | null = null
     if (mapped.vatUnresolved) {
       result.vatUnresolved++
     } else if (headerHoldsNoVatEvidence(row)) {
@@ -381,36 +383,55 @@ export async function completeMigratedInvoiceLines(
     return result
   }
 
+  // One run, one correlation id: the invoices this run completed read as
+  // one thread in the behandlingshistorik.
+  const trail: CompleteInvoiceRowsTrail = {
+    source: COMPLETE_INVOICE_LINES_SOURCE,
+    provider,
+    consentId,
+    correlationId: crypto.randomUUID(),
+    actor,
+  }
+
   for (const plan of planned) {
     // One call per invoice, so a bad row set rejects its own invoice and not
     // the hundred beside it. A concurrent run (the wizard and the cron, or
     // two crons overlapping) that filled this invoice since the candidates
-    // were loaded leaves this call with wrote = false: rows are appended,
-    // never replaced, and the RPC's invoice lock is what keeps a second
-    // writer from doubling them.
-    const { data, error } = await supabase.rpc('complete_invoice_rows', {
-      p_company_id: companyId,
-      p_invoice_id: plan.row.id,
-      p_rows: plan.items,
-      p_header: plan.header,
+    // were loaded leaves this call already_filled: rows are appended, never
+    // replaced, and the RPC's invoice lock is what keeps a second writer
+    // from doubling them. The trail event is written only for a write that
+    // landed, by completeInvoiceRows itself.
+    const outcome = await completeInvoiceRows(supabase, {
+      companyId,
+      invoiceId: plan.row.id,
+      rows: plan.items,
+      header: plan.header,
+      headerBefore: {
+        subtotal: plan.row.subtotal,
+        vat_amount: plan.row.vat_amount,
+        vat_rate: plan.row.vat_rate,
+        vat_treatment: plan.row.vat_treatment,
+      },
+      trail,
+      // The cron's client is the service client already.
+      historyClient: supabase,
     })
-    const outcome = (data ?? null) as CompleteRowsOutcome | null
-    if (error || !outcome?.ok) {
+    if (outcome.status === 'failed') {
       result.failed++
       log.error('complete_invoice_rows failed', {
-        companyId, invoiceId: plan.row.id, invoiceNumber: plan.row.invoice_number,
-        reason: error?.message ?? outcome?.code ?? 'empty RPC response',
+        companyId, invoiceId: plan.row.id, invoiceNumber: plan.row.invoice_number, reason: outcome.reason,
       })
       continue
     }
-    if (!outcome.wrote) {
+    if (outcome.status === 'already_filled') {
       log.info('invoice gained rows since the candidates were loaded; left as is', {
         companyId, invoiceId: plan.row.id,
       })
       continue
     }
     result.completed++
-    if (outcome.header_updated) result.headersUpdated++
+    if (outcome.headerUpdated) result.headersUpdated++
+    if (outcome.eventId) result.historyAppended++
   }
 
   result.remaining = candidates.length - result.completed
@@ -424,6 +445,7 @@ export async function completeMigratedInvoiceLines(
     totalMismatch: result.totalMismatch,
     rowsMismatch: result.rowsMismatch,
     failed: result.failed,
+    historyAppended: result.historyAppended,
     remaining: result.remaining,
     hydration: result.hydration,
   })
diff --git a/extensions/general/arcim-migration/lib/migration-orchestrator.ts b/extensions/general/arcim-migration/lib/migration-orchestrator.ts
index 8d383ee7..d1704065 100644
--- a/extensions/general/arcim-migration/lib/migration-orchestrator.ts
+++ b/extensions/general/arcim-migration/lib/migration-orchestrator.ts
@@ -40,6 +40,7 @@ import { fetchAllRows } from '@/lib/supabase/fetch-all'
 import { suggestPartiesForCompany } from '@/lib/parties/suggest'
 import { createLogger } from '@/lib/logger'
 import { reconcileSupplierInvoiceVouchers } from '@/lib/invoices/bulk-reconcile-supplier-vouchers'
+import { completeInvoiceRows, type CompleteInvoiceRowsTrail } from '@/lib/invoices/complete-invoice-rows'
 import {
   linkMigratedRegistrationVouchers,
   type MigratedInvoiceLinkInput,
@@ -69,6 +70,14 @@ export interface MigrationOptions {
   companyId: string
   userId: string
   supabase: SupabaseClient
+  /**
+   * Service-role client for the behandlingshistorik rows the sales-invoice
+   * step writes (processing_history has no INSERT policy, and `supabase` is
+   * the user's session client). Resolved once, and only when there are rows
+   * to write, so a run that imports nothing invoice-shaped never builds it.
+   * See lib/invoices/complete-invoice-rows.ts.
+   */
+  createHistoryClient: () => Promise<Pick<SupabaseClient, 'from'>>
   importCompanyInfo?: boolean
   importCustomers?: boolean
   importSuppliers?: boolean
@@ -88,6 +97,8 @@ export interface MigrationOptions {
 const INSERT_CHUNK_SIZE = 500
 /** Sales-invoice row writes in flight at once (one complete_invoice_rows call per invoice). */
 const ITEM_RPC_CONCURRENCY = 8
+/** The writer named in the behandlingshistorik event for every invoice's rows. */
+export const MIGRATION_WIZARD_SOURCE = 'migration-wizard'
 const ENRICHMENT_CONCURRENCY = 10
 
 function emitProgress(options: MigrationOptions, progress: MigrationProgress) {
@@ -210,6 +221,9 @@ function logFxUnresolved(kind: string, invoiceNumber: string, fx: FxUnresolved):
 export async function executeMigration(options: MigrationOptions): Promise<MigrationResults> {
   const { consentId, companyId, userId, supabase } = options
   const results: MigrationResults = {}
+  // One id per run: every InvoiceRowsCompleted event this import writes
+  // shares it, so the import reads as one thread in the behandlingshistorik.
+  const runId = crypto.randomUUID()
   // What this run has proven about the grant, read by recordStepError: a 403
   // once a call has already succeeded is one closed register, not a dead token.
   const runState: ProviderRunState = { grantProven: false }
@@ -779,22 +793,36 @@ export async function executeMigration(options: MigrationOptions): Promise<Migra
           // an invoice's rows are written at most once whichever writer gets
           // there first, and a bad row set rejects its own invoice rather than
           // the whole chunk. Small concurrent groups keep the round trips off
-          // the wizard's clock.
-          for (const group of chunk(rowsByInvoice, ITEM_RPC_CONCURRENCY)) {
-            await Promise.all(group.map(async ({ invoiceId, rows }) => {
-              const { data, error: itemErr } = await supabase.rpc('complete_invoice_rows', {
-                p_company_id: companyId,
-                p_invoice_id: invoiceId,
-                p_rows: rows,
-              })
-              const rpcOutcome = (data ?? null) as { ok?: boolean; code?: string } | null
-              if (itemErr || !rpcOutcome?.ok) {
-                console.error(
-                  `[migration] Sales invoice items insert failed for ${invoiceId}:`,
-                  itemErr?.message ?? rpcOutcome?.code ?? 'empty RPC response',
-                )
-              }
-            }))
+          // the wizard's clock. completeInvoiceRows also writes the
+          // InvoiceRowsCompleted event for every invoice the RPC filled, the
+          // same event the pass writes, so the two writers reconcile per
+          // invoice (BFNAR 2013:2 p. 9.16).
+          if (rowsByInvoice.length > 0) {
+            const historyClient = await options.createHistoryClient()
+            const trail: CompleteInvoiceRowsTrail = {
+              source: MIGRATION_WIZARD_SOURCE,
+              provider,
+              consentId,
+              correlationId: runId,
+              actor: { type: 'user', id: userId },
+            }
+            for (const group of chunk(rowsByInvoice, ITEM_RPC_CONCURRENCY)) {
+              await Promise.all(group.map(async ({ invoiceId, rows }) => {
+                const outcome = await completeInvoiceRows(supabase, {
+                  companyId,
+                  invoiceId,
+                  rows,
+                  trail,
+                  historyClient,
+                })
+                if (outcome.status === 'failed') {
+                  console.error(
+                    `[migration] Sales invoice items insert failed for ${invoiceId}:`,
+                    outcome.reason,
+                  )
+                }
+              }))
+            }
           }
         }
 
diff --git a/lib/invoices/__tests__/complete-invoice-rows.test.ts b/lib/invoices/__tests__/complete-invoice-rows.test.ts
new file mode 100644
index 00000000..debbe1e8
--- /dev/null
+++ b/lib/invoices/__tests__/complete-invoice-rows.test.ts
@@ -0,0 +1,204 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { PROCESSING_EVENT_TYPES } from '@/lib/processing-history/append'
+import {
+  completeInvoiceRows,
+  INVOICE_ROWS_COMPLETED_EVENT,
+  type CompleteInvoiceRowsTrail,
+} from '../complete-invoice-rows'
+
+/**
+ * The one call site for complete_invoice_rows and the one emitter of the
+ * InvoiceRowsCompleted behandlingshistorik event (#2312). The append runs for
+ * real against a spy client: what lands in processing_history is the row
+ * shape and the PII guard of appendProcessingHistoryWithClient, not a mock's
+ * idea of it. The RPC is a spy.
+ */
+
+vi.mock('@/lib/supabase/server', () => ({
+  createClient: vi.fn(),
+  createServiceClient: vi.fn(),
+}))
+
+const COMPANY = '11111111-1111-4111-8111-111111111111'
+const INVOICE = '22222222-2222-4222-8222-222222222222'
+const CONSENT = '33333333-3333-4333-8333-333333333333'
+const RUN = '44444444-4444-4444-8444-444444444444'
+
+const ROWS = [
+  { sort_order: 1, description: 'Konsulttid', quantity: 8, unit: 'h', unit_price: 100, line_total: 800, vat_rate: 25, vat_amount: 200, line_type: 'product' },
+  { sort_order: 2, description: 'Resa', quantity: 1, unit: 'st', unit_price: 200, line_total: 200, vat_rate: 25, vat_amount: 50, line_type: 'product' },
+]
+
+const HEADER = {
+  subtotal: 1000,
+  subtotal_sek: 1000,
+  vat_amount: 250,
+  vat_amount_sek: 250,
+  vat_rate: 25,
+  vat_treatment: 'standard_25',
+}
+
+/** The pre-#1745 shape: 25 % label beside 0 kr VAT and subtotal = total. */
+const BEFORE = { subtotal: 1250, vat_amount: 0, vat_rate: 25, vat_treatment: 'standard_25' }
+
+const trail: CompleteInvoiceRowsTrail = {
+  source: 'complete-invoice-lines',
+  provider: 'fortnox',
+  consentId: CONSENT,
+  correlationId: RUN,
+  actor: { type: 'cron', id: 'complete-invoice-lines' },
+}
+
+function rpcClient(reply: { data?: unknown; error?: { message: string } | null }) {
+  const rpc = vi.fn().mockResolvedValue({ data: reply.data ?? null, error: reply.error ?? null })
+  return { client: { rpc } as never, rpc }
+}
+
+function historyClient(error: { message: string } | null = null) {
+  const insert = vi.fn().mockResolvedValue({ error })
+  const from = vi.fn().mockReturnValue({ insert })
+  return { client: { from } as never, from, insert }
+}
+
+const wrote = (rows: number, headerUpdated: boolean) => ({
+  data: { ok: true, wrote: true, rows, header_updated: headerUpdated },
+})
+
+describe('completeInvoiceRows', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('names an event type the catalog registers', () => {
+    // The union already refuses an unregistered literal at compile time;
+    // this pins the runtime list the pg test reads against the migration.
+    expect(PROCESSING_EVENT_TYPES).toContain(INVOICE_ROWS_COMPLETED_EVENT)
+  })
+
+  it('writes through the RPC and appends one InvoiceRowsCompleted on the invoice, with the split before and after', async () => {
+    const { client: supabase, rpc } = rpcClient(wrote(2, true))
+    const history = historyClient()
+
+    const result = await completeInvoiceRows(supabase, {
+      companyId: COMPANY,
+      invoiceId: INVOICE,
+      rows: ROWS,
+      header: HEADER,
+      headerBefore: BEFORE,
+      trail,
+      historyClient: history.client,
+    })
+
+    expect(rpc).toHaveBeenCalledTimes(1)
+    expect(rpc).toHaveBeenCalledWith('complete_invoice_rows', {
+      p_company_id: COMPANY,
+      p_invoice_id: INVOICE,
+      p_rows: ROWS,
+      p_header: HEADER,
+    })
+
+    expect(history.from).toHaveBeenCalledWith('processing_history')
+    expect(history.insert).toHaveBeenCalledTimes(1)
+    const row = history.insert.mock.calls[0][0] as Record<string, unknown>
+    expect(row).toMatchObject({
+      company_id: COMPANY,
+      correlation_id: RUN,
+      aggregate_type: 'Invoice',
+      aggregate_id: INVOICE,
+      event_type: 'InvoiceRowsCompleted',
+      actor: { type: 'cron', id: 'complete-invoice-lines' },
+      payload_schema_version: 1,
+    })
+    expect(row.payload).toEqual({
+      source: 'complete-invoice-lines',
+      provider: 'fortnox',
+      consent_id: CONSENT,
+      rows: 2,
+      header_updated: true,
+      header_before: { subtotal: 1250, vat_amount: 0, vat_rate: 25, vat_treatment: 'standard_25' },
+      header_after: { subtotal: 1000, vat_amount: 250, vat_rate: 25, vat_treatment: 'standard_25' },
+    })
+    // The SEK twins are derived, not evidence: the trail leaves them out.
+    expect(row.payload).not.toHaveProperty('header_after.subtotal_sek')
+
+    expect(result).toEqual({ status: 'written', rows: 2, headerUpdated: true, eventId: row.event_id })
+    expect(typeof result.status === 'string' && 'eventId' in result && result.eventId).toMatch(/^[0-9a-f-]{36}$/)
+  })
+
+  it('records no split when the header was left alone (the wizard path, or evidence already there)', async () => {
+    const { client: supabase, rpc } = rpcClient(wrote(2, false))
+    const history = historyClient()
+
+    const result = await completeInvoiceRows(supabase, {
+      companyId: COMPANY,
+      invoiceId: INVOICE,
+      rows: ROWS,
+      trail: { ...trail, source: 'migration-wizard', actor: { type: 'user', id: '55555555-5555-4555-8555-555555555555' } },
+      historyClient: history.client,
+    })
+
+    // No header means an explicit null to the RPC, never a dropped argument.
+    expect(rpc.mock.calls[0][1]).toMatchObject({ p_header: null })
+    const row = history.insert.mock.calls[0][0] as Record<string, unknown>
+    expect(row.payload).toEqual({
+      source: 'migration-wizard',
+      provider: 'fortnox',
+      consent_id: CONSENT,
+      rows: 2,
+      header_updated: false,
+      header_before: null,
+      header_after: null,
+    })
+    expect(row.actor).toEqual({ type: 'user', id: '55555555-5555-4555-8555-555555555555' })
+    expect(result).toMatchObject({ status: 'written', rows: 2, headerUpdated: false })
+  })
+
+  it('records nothing when another writer filled the invoice first', async () => {
+    const { client: supabase } = rpcClient({ data: { ok: true, wrote: false, rows: 0, header_updated: false } })
+    const history = historyClient()
+
+    const result = await completeInvoiceRows(supabase, {
+      companyId: COMPANY, invoiceId: INVOICE, rows: ROWS, header: HEADER, headerBefore: BEFORE, trail,
+      historyClient: history.client,
+    })
+
+    expect(result).toEqual({ status: 'already_filled' })
+    expect(history.insert).not.toHaveBeenCalled()
+  })
+
+  it('records nothing when the RPC errors or refuses', async () => {
+    const history = historyClient()
+
+    const errored = rpcClient({ data: null, error: { message: 'check violation' } })
+    await expect(completeInvoiceRows(errored.client, {
+      companyId: COMPANY, invoiceId: INVOICE, rows: ROWS, trail, historyClient: history.client,
+    })).resolves.toEqual({ status: 'failed', reason: 'check violation' })
+
+    const refused = rpcClient({ data: { ok: false, code: 'MISSING_REQUIRED', details: { column: 'vat_rate' } } })
+    await expect(completeInvoiceRows(refused.client, {
+      companyId: COMPANY, invoiceId: INVOICE, rows: ROWS, trail, historyClient: history.client,
+    })).resolves.toEqual({ status: 'failed', reason: 'MISSING_REQUIRED' })
+
+    const empty = rpcClient({ data: null })
+    await expect(completeInvoiceRows(empty.client, {
+      companyId: COMPANY, invoiceId: INVOICE, rows: ROWS, trail, historyClient: history.client,
+    })).resolves.toEqual({ status: 'failed', reason: 'empty RPC response' })
+
+    expect(history.insert).not.toHaveBeenCalled()
+  })
+
+  it('reports a write whose trail append failed as written, with no event id', async () => {
+    // The rows are committed by then. Failing the invoice would make the
+    // next run try again and find it full; the gap is logged instead.
+    const { client: supabase } = rpcClient(wrote(2, true))
+    const history = historyClient({ message: 'insert or update on table "processing_history" violates foreign key constraint' })
+
+    const result = await completeInvoiceRows(supabase, {
+      companyId: COMPANY, invoiceId: INVOICE, rows: ROWS, header: HEADER, headerBefore: BEFORE, trail,
+      historyClient: history.client,
+    })
+
+    expect(history.insert).toHaveBeenCalledTimes(1)
+    expect(result).toEqual({ status: 'written', rows: 2, headerUpdated: true, eventId: null })
+  })
+})
diff --git a/lib/invoices/complete-invoice-rows.ts b/lib/invoices/complete-invoice-rows.ts
new file mode 100644
index 00000000..e0ea353b
--- /dev/null
+++ b/lib/invoices/complete-invoice-rows.ts
@@ -0,0 +1,189 @@
+/**
+ * completeInvoiceRows: the one TypeScript call site for the
+ * complete_invoice_rows RPC (migration 20260906135730), and the one place the
+ * behandlingshistorik event for a completed migrated invoice is written.
+ *
+ * Two writers put rows under migrated sales invoices: the migration wizard
+ * (extensions/general/arcim-migration/lib/migration-orchestrator.ts, rows
+ * written milliseconds after the header) and the hourly row-completion pass
+ * (complete-invoice-lines.ts, the rows the wizard's hydration budget did not
+ * reach, plus the header VAT split when the stored one held no evidence).
+ * The RPC already gives them one write path; this wrapper gives them one
+ * trail. Every invoice whose rows the RPC wrote gets one InvoiceRowsCompleted
+ * event (BFL 5 kap 11 §, BFNAR 2013:2 p. 9.16: the behandlingshistorik has to
+ * say what was processed automatically, when, and by what) naming the writer,
+ * the provider the rows came from, the row count and, when the header split
+ * was rewritten, the split before and after. The pass writes no
+ * bokföringspost, so BFL 5 kap 5 § (rättelse) does not bind it; the migration
+ * that wrote the invoice header records no event of its own, so this event
+ * is what lets the two writers reconcile per invoice.
+ *
+ * Failure semantics: the event is written only after the RPC has answered
+ * wrote = true, so an invoice whose completion failed, or that another writer
+ * had already filled, gets no event. The append itself is best-effort, the
+ * convention every processing_history writer follows (the rows are
+ * committed; a missing change-log row is logged, not turned into a failed
+ * invoice that the next run would try again and find full). The caller sees
+ * a null eventId when that happened.
+ *
+ * PII boundary: the payload carries UUIDs, counts, amounts and enum strings
+ * only. Invoice numbers and provider document numbers are deliberately left
+ * out: a ten-digit number (2026090001) trips the personnummer guard in
+ * appendProcessingHistory, which would lose the event for exactly that
+ * invoice. The invoice id is the reference; its number is on the row.
+ */
+
+import type { SupabaseClient } from '@supabase/supabase-js'
+import type { ProcessingHistoryActor } from '@/types'
+import { createLogger } from '@/lib/logger'
+import {
+  appendProcessingHistoryWithClient,
+  type ProcessingHistoryEventType,
+} from '@/lib/processing-history/append'
+
+const log = createLogger('invoices/complete-invoice-rows')
+
+/** Registered in processing_event_types by migration 20260906210100. */
+export const INVOICE_ROWS_COMPLETED_EVENT = 'InvoiceRowsCompleted' satisfies ProcessingHistoryEventType
+
+type RpcClient = Pick<SupabaseClient, 'rpc'>
+type HistoryClient = Pick<SupabaseClient, 'from'>
+
+/** The six invoice columns the RPC may rewrite: all present or none. */
+export interface InvoiceHeaderVatSplit {
+  subtotal: number
+  subtotal_sek: number | null
+  vat_amount: number
+  vat_amount_sek: number | null
+  vat_rate: number | null
+  vat_treatment: string
+}
+
+/**
+ * What the trail records of a header split. The SEK twins are left out:
+ * they are derived from these and the exchange rate the row already carries.
+ */
+export interface InvoiceHeaderVatSnapshot {
+  subtotal: number | null
+  vat_amount: number | null
+  vat_rate: number | null
+  vat_treatment: string | null
+}
+
+export interface CompleteInvoiceRowsTrail {
+  /** Which writer: 'migration-wizard' or 'complete-invoice-lines'. */
+  source: string
+  /** The provider the rows came from ('fortnox', 'briox', ...). */
+  provider: string
+  /** The provider consent the rows were fetched under. */
+  consentId: string
+  /** One id per run, shared by every invoice the run completed. */
+  correlationId: string
+  actor: ProcessingHistoryActor
+}
+
+export interface CompleteInvoiceRowsInput {
+  companyId: string
+  invoiceId: string
+  /** The invoice_items columns per row; the RPC stamps invoice_id itself. */
+  rows: Record<string, unknown>[]
+  /** The header split to apply in the same transaction, or null to leave the header alone. */
+  header?: InvoiceHeaderVatSplit | null
+  /** The stored split before the write; recorded beside the new one when the header is rewritten. */
+  headerBefore?: InvoiceHeaderVatSnapshot | null
+  trail: CompleteInvoiceRowsTrail
+  /**
+   * The client the event row is written with. processing_history has no
+   * INSERT policy, so this must be a service-role client: the cron's own
+   * client already is, the wizard (on the user's session client) passes one.
+   */
+  historyClient: HistoryClient
+}
+
+export type CompleteInvoiceRowsResult =
+  /** The rows (and the header, when one was given) landed; eventId is null when the trail append failed. */
+  | { status: 'written'; rows: number; headerUpdated: boolean; eventId: string | null }
+  /** Another writer filled the invoice first; nothing was written and nothing is recorded. */
+  | { status: 'already_filled' }
+  /** The RPC errored or refused (its code, or the Postgres message). */
+  | { status: 'failed'; reason: string }
+
+/** What complete_invoice_rows returns (migration 20260906135730). */
+interface CompleteRowsRpcOutcome {
+  ok: boolean
+  code?: string
+  wrote?: boolean
+  rows?: number
+  header_updated?: boolean
+}
+
+function snapshotOf(split: InvoiceHeaderVatSnapshot | InvoiceHeaderVatSplit | null | undefined): InvoiceHeaderVatSnapshot | null {
+  if (!split) return null
+  return {
+    subtotal: split.subtotal,
+    vat_amount: split.vat_amount,
+    vat_rate: split.vat_rate,
+    vat_treatment: split.vat_treatment,
+  }
+}
+
+export async function completeInvoiceRows(
+  supabase: RpcClient,
+  input: CompleteInvoiceRowsInput,
+): Promise<CompleteInvoiceRowsResult> {
+  const header = input.header ?? null
+  const { data, error } = await supabase.rpc('complete_invoice_rows', {
+    p_company_id: input.companyId,
+    p_invoice_id: input.invoiceId,
+    p_rows: input.rows,
+    p_header: header,
+  })
+  const outcome = (data ?? null) as CompleteRowsRpcOutcome | null
+  if (error || !outcome?.ok) {
+    return { status: 'failed', reason: error?.message ?? outcome?.code ?? 'empty RPC response' }
+  }
+  if (!outcome.wrote) return { status: 'already_filled' }
+
+  const rows = outcome.rows ?? input.rows.length
+  const headerUpdated = outcome.header_updated === true
+  const eventId = await appendCompletedEvent(input, rows, headerUpdated)
+  return { status: 'written', rows, headerUpdated, eventId }
+}
+
+async function appendCompletedEvent(
+  input: CompleteInvoiceRowsInput,
+  rows: number,
+  headerUpdated: boolean,
+): Promise<string | null> {
+  const { trail } = input
+  try {
+    return await appendProcessingHistoryWithClient(input.historyClient, {
+      companyId: input.companyId,
+      correlationId: trail.correlationId,
+      aggregateType: 'Invoice',
+      aggregateId: input.invoiceId,
+      eventType: INVOICE_ROWS_COMPLETED_EVENT,
+      payload: {
+        source: trail.source,
+        provider: trail.provider,
+        consent_id: trail.consentId,
+        rows,
+        header_updated: headerUpdated,
+        header_before: headerUpdated ? snapshotOf(input.headerBefore) : null,
+        header_after: headerUpdated ? snapshotOf(input.header) : null,
+      },
+      actor: trail.actor,
+      occurredAt: new Date(),
+    })
+  } catch (err) {
+    // The rows are committed; the trail row is what is missing. Logged so
+    // the gap is visible, never a reason to report the invoice as failed.
+    log.error('InvoiceRowsCompleted append failed; rows written without their behandlingshistorik row', {
+      companyId: input.companyId,
+      invoiceId: input.invoiceId,
+      source: trail.source,
+      error: err instanceof Error ? err.message : String(err),
+    })
+    return null
+  }
+}
diff --git a/lib/processing-history/append.ts b/lib/processing-history/append.ts
index 96b15cab..90517b41 100644
--- a/lib/processing-history/append.ts
+++ b/lib/processing-history/append.ts
@@ -60,6 +60,7 @@ export const PROCESSING_EVENT_TYPES = [
   'InvoiceDuplicatePaymentDismissed',
   'InvoiceJournalEntrySkipped',
   'InvoicePaymentRowBackfilled',
+  'InvoiceRowsCompleted',
   'OAuthClientRevoked',
   'PendingOperationApproved',
   'PendingOperationRejected',
diff --git a/supabase/migrations/20260906210100_invoice_rows_completed_event.sql b/supabase/migrations/20260906210100_invoice_rows_completed_event.sql
new file mode 100644
index 00000000..c833db10
--- /dev/null
+++ b/supabase/migrations/20260906210100_invoice_rows_completed_event.sql
@@ -0,0 +1,54 @@
+-- InvoiceRowsCompleted: the behandlingshistorik event for a migrated sales
+-- invoice whose rows were written by complete_invoice_rows (migration
+-- 20260906135730), from either of its writers: the migration wizard or the
+-- hourly row-completion pass (#2291, #2312).
+--
+-- The pass inserts invoice_items and rewrites the header VAT split on
+-- invoices whose stored split held no evidence. It writes no bokföringspost,
+-- so BFL 5 kap 5 § (rättelse) does not bind it, but it is automated
+-- processing of räkenskapsinformation, which BFL 5 kap 11 § and BFNAR 2013:2
+-- p. 9.16 want in the behandlingshistorik: what was processed, when, and by
+-- what. Until now the only trail was a log line per invoice in Vercel, and
+-- the migration that wrote the invoices in the first place records no event
+-- either.
+--
+-- One event per completed invoice, emitted by lib/invoices/complete-invoice-
+-- rows.ts (the one TypeScript call site for the RPC, so a writer cannot reach
+-- the RPC without the trail). Payload: the writer, the provider, the consent,
+-- the row count, and the header split before and after when it was
+-- rewritten. UUIDs, counts, amounts and enum strings only.
+--
+-- The aggregate is the invoice, which the aggregate_type CHECK did not admit
+-- (no invoice-level event existed before). 'Invoice' is added the way
+-- 20260423140500 added the AI streams; every value already in the constraint
+-- stays. The catalog row goes in as for every other event type:
+-- processing_history.event_type has an FK to it and the append is
+-- best-effort, so an unregistered type would be lost silently
+-- (lib/processing-history/append.ts, tests/pg/processing-event-types.pg.test.ts).
+--
+-- pg-test: tests/pg/invoice-rows-completed-event.pg.test.ts
+
+ALTER TABLE public.processing_history
+  DROP CONSTRAINT IF EXISTS processing_history_aggregate_type_check;
+
+ALTER TABLE public.processing_history
+  ADD CONSTRAINT processing_history_aggregate_type_check
+  CHECK (aggregate_type IN (
+    'Document',
+    'BankTransaction',
+    'MatchProposal',
+    'Verifikation',
+    'CounterpartyTemplate',
+    'Period',
+    'Migration',
+    'System',
+    'AIProposal',
+    'AIRequest',
+    'Invoice'
+  ));
+
+INSERT INTO public.processing_event_types (event_type)
+VALUES ('InvoiceRowsCompleted')
+ON CONFLICT (event_type) DO NOTHING;
+
+NOTIFY pgrst, 'reload schema';
diff --git a/tests/pg/invoice-rows-completed-event.pg.test.ts b/tests/pg/invoice-rows-completed-event.pg.test.ts
new file mode 100644
index 00000000..4f01c5f3
--- /dev/null
+++ b/tests/pg/invoice-rows-completed-event.pg.test.ts
@@ -0,0 +1,66 @@
+import { describe, it, expect } from 'vitest'
+import { randomUUID } from 'node:crypto'
+import { getPool } from './setup'
+import { seedCompany } from './fixtures'
+
+// pg-real coverage for 20260906210100_invoice_rows_completed_event: the
+// behandlingshistorik event lib/invoices/complete-invoice-rows.ts writes for
+// every migrated invoice whose rows complete_invoice_rows filled (#2312).
+// The type must be in the catalog (the append is best-effort, so an
+// unregistered type is a silently lost record) and the invoice must be an
+// admitted aggregate (the CHECK did not know 'Invoice' before).
+
+describe('migration 20260906210100: InvoiceRowsCompleted event', () => {
+  it('registers InvoiceRowsCompleted in the processing history catalog', async () => {
+    const { rows } = await getPool().query(
+      `SELECT event_type
+       FROM public.processing_event_types
+       WHERE event_type = 'InvoiceRowsCompleted'`,
+    )
+
+    expect(rows).toEqual([{ event_type: 'InvoiceRowsCompleted' }])
+  })
+
+  it('accepts the event on the Invoice aggregate, shaped the way the emitter writes it', async () => {
+    const { companyId } = await seedCompany()
+    const invoiceId = randomUUID()
+    const runId = randomUUID()
+    const { rows } = await getPool().query<{ aggregate_type: string; event_type: string }>(
+      `INSERT INTO public.processing_history
+         (company_id, correlation_id, aggregate_type, aggregate_id, event_type, payload, actor, occurred_at)
+       VALUES ($1, $2, 'Invoice', $3, 'InvoiceRowsCompleted',
+               $4::jsonb, '{"type":"cron","id":"complete-invoice-lines"}', now())
+       RETURNING aggregate_type, event_type`,
+      [
+        companyId,
+        runId,
+        invoiceId,
+        JSON.stringify({
+          source: 'complete-invoice-lines',
+          provider: 'fortnox',
+          consent_id: randomUUID(),
+          rows: 2,
+          header_updated: true,
+          header_before: { subtotal: 1250, vat_amount: 0, vat_rate: 25, vat_treatment: 'standard_25' },
+          header_after: { subtotal: 1000, vat_amount: 250, vat_rate: 25, vat_treatment: 'standard_25' },
+        }),
+      ],
+    )
+
+    expect(rows).toEqual([{ aggregate_type: 'Invoice', event_type: 'InvoiceRowsCompleted' }])
+  })
+
+  it('still refuses an aggregate the constraint does not name: the CHECK was widened, not dropped', async () => {
+    const { companyId } = await seedCompany()
+    const id = randomUUID()
+    await expect(
+      getPool().query(
+        `INSERT INTO public.processing_history
+           (company_id, correlation_id, aggregate_type, aggregate_id, event_type, payload, actor, occurred_at)
+         VALUES ($1, $2, 'Kitten', $2, 'InvoiceRowsCompleted', '{}'::jsonb,
+                 '{"type":"system","id":"invoice-rows-completed-test"}', now())`,
+        [companyId, id],
+      ),
+    ).rejects.toMatchObject({ code: '23514' })
+  })
+})
diff --git a/types/index.ts b/types/index.ts
index 14d49e9a..2cb6f0ef 100644
--- a/types/index.ts
+++ b/types/index.ts
@@ -293,6 +293,7 @@ export type ProcessingHistoryAggregateType =
   | 'Period'
   | 'Migration'
   | 'System'
+  | 'Invoice'
 
 // Bank connection status
 // 'pending_selection' = PSD2 consent granted, awaiting user to pick which