fix(settings): scope cross-field VAT validations to saves that touch them (#2121)

* fix(settings): scope cross-field VAT validations to saves that touch them

The settings PUT validated the whole effective record on every partial
update, so companies stored as vat_registered without a vat_number were
blocked from saving anything through the endpoint, including the invoice
bank-details dialog, which has no VAT fields (reported by a user stuck on
"Momsregistreringsnummer kravs...").

Each cross-field check (VAT completeness, 40m-monthly, periodisk
sammanstallning) now runs only when the request body touches a field in
its group, so the invariant still holds whenever VAT config is edited.
Explicit null now counts as clearing a value during validation instead of
falling back to the stored one, closing a latent hole where
{ vat_number: null } passed validation but wrote null.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016fjJLUucErb1ZHyQ57fe1u

* fix(invoices): gate issuance on the seller VAT number (skeptic finding)

The settings scoping in the previous commit removed what was accidentally
the only enforcement of "momsregistrerad implies momsregnr on file": with
bank details saveable again, a registered company without a stored VAT
number could issue a faktura charging moms with no seller VAT number in
the footer (mandatory element, ML (2023:200) 17 kap. 24 §).

Issuance is now gated the same way the payment account is, at all four
independent issuance points (issueAndBookInvoice, dashboard send, v1 send,
v1 mark-sent), with a structured error pointing at Installningar -> Skatt.
Credit notes, proformas, and delivery notes are exempt like the payment
gate exempts them.

Also, per the Swedish review and the secondary skeptic finding:
- PS/EU-trade edits join the VAT-completeness touch group, so enabling
  periodisk sammanstallning on an incomplete registration keeps failing.
- The stale ML 11 kap. 8 citation is updated to ML 17 kap. 24.

The makeCompanySettings fixture now models a coherent registered company
(vat_number set); the missing-number tests override it explicitly.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016fjJLUucErb1ZHyQ57fe1u

* fix(invoices): extend the seller-VAT-number gate to the headless issuance paths

Skeptic round 2 found three more issuance points beside the four gated in
the previous commit: the recurring auto-send service (cron, no human in
the loop), and the MCP staged-operation executors send_invoice and
mark_invoice_sent. Each carried the payment-account gate but not the VAT
gate; mark_invoice_sent additionally had a narrow settings select that
would have made a naive gate silently pass, now widened.

Recurring auto-send fails soft, matching its other guards: the invoice
stays a numbered draft with the standard schedule warning. The executors
return the structured Swedish message. Peppol send was verified
self-gating (BIS preflight requires the supplier VAT number).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016fjJLUucErb1ZHyQ57fe1u

* test(email): refresh brand-mail snapshots for the coherent VAT fixture

The makeCompanySettings fixture now carries a VAT number, so the invoice
and reminder mail footers correctly render the VAT line; the snapshots
predate that. Also cites ML 17 kap. 22-23 (andringsfaktura content list)
in the seller-vat-number docstring per the Swedish review suggestion,
documenting why credit notes are exempt. No behavior change.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016fjJLUucErb1ZHyQ57fe1u

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

app/api/invoices/[id]/send/__tests__/route.test.ts

@@ -390,6 +390,20 @@ describe('POST /api/invoices/[id]/send', () => {
     },
   )
 
+  it('does not allocate a number or send when the registered company has no VAT number', async () => {
+    enqueue({ data: makeInvoice({ ...invoice, invoice_number: null }), error: null })
+    enqueue({ data: { ...company, vat_registered: true, vat_number: null }, error: null })
+
+    const request = createMockRequest('/api/invoices/inv-1/send', { method: 'POST' })
+    const response = await POST(request, createMockRouteParams({ id: 'inv-1' }))
+    const { status, body } = await parseJsonResponse<{ error: { code: string } }>(response)
+
+    expect(status).toBe(400)
+    expect(body.error.code).toBe('INVOICE_SEND_VAT_NUMBER_MISSING')
+    expect(mockReserveInvoiceDelivery).not.toHaveBeenCalled()
+    expect(mockSendEmail).not.toHaveBeenCalled()
+  })
+
   it('rejects custom recipients from a non-admin company member before allocation', async () => {
     enqueue({ data: invoice, error: null })
     enqueue({ data: company, error: null })

app/api/invoices/[id]/send/route.ts

@@ -41,6 +41,7 @@ import {
   hasRequiredInvoicePaymentAccount,
   invoiceRequiresPaymentAccount,
 } from '@/lib/invoices/payment-accounts'
+import { hasRequiredSellerVatNumber } from '@/lib/invoices/seller-vat-number'
 import { errorResponseFromCode } from '@/lib/errors/get-structured-error'
 import { guardSandbox } from '@/lib/sandbox/guard'
 import { requireCapability } from '@/lib/entitlements/has-capability'
@@ -197,6 +198,10 @@ export const POST = withRouteContext(
       })
     }
 
+    if (!hasRequiredSellerVatNumber(company as CompanySettings, invoice as Invoice)) {
+      return errorResponseFromCode('INVOICE_SEND_VAT_NUMBER_MISSING', opLog, { requestId })
+    }
+
     const hasAdditionalRecipients =
       (bodyResult.data.additional_cc?.length ?? 0) > 0
       || (bodyResult.data.additional_bcc?.length ?? 0) > 0

app/api/settings/__tests__/route.test.ts

@@ -716,4 +716,148 @@ describe('PUT /api/settings', () => {
 
     expect(response.status).toBe(400)
   })
+
+  it('allows a bank-details save when stored VAT state is incomplete (bank dialog)', async () => {
+    // Pre-existing inconsistency: registered without a VAT number. The invoice
+    // bank-details dialog has no VAT fields and must not be blocked by it.
+    const settings = {
+      entity_type: 'aktiebolag',
+      vat_registered: true,
+      vat_number: null,
+      moms_period: 'quarterly',
+      onboarding_complete: true,
+    }
+    enqueueMany([
+      { data: settings },                                         // oldSettings
+      { data: { role: 'owner' } },                                // payment-instructions role gate
+      { data: { id: 's1', bank_name: 'Testbanken', bankgiro: '223-8194' } }, // update
+      { data: null, count: 5 },                                   // deadlines count
+    ])
+
+    const response = await PUT(createMockRequest('/api/settings', {
+      method: 'PUT',
+      body: { bank_name: 'Testbanken', bankgiro: '223-8194' },
+    }), { params: Promise.resolve({}) })
+    const { status } = await parseJsonResponse(response)
+
+    expect(status).toBe(200)
+  })
+
+  it('still rejects enabling VAT registration without a VAT number', async () => {
+    enqueue({
+      data: {
+        entity_type: 'aktiebolag',
+        vat_registered: false,
+        vat_number: null,
+        moms_period: 'quarterly',
+        onboarding_complete: true,
+      },
+    })
+
+    const response = await PUT(createMockRequest('/api/settings', {
+      method: 'PUT',
+      body: { vat_registered: true },
+    }), { params: Promise.resolve({}) })
+    const { status, body } = await parseJsonResponse<{ error: string }>(response)
+
+    expect(status).toBe(400)
+    expect(body.error).toContain('Momsregistreringsnummer')
+    expect(supabase.from).toHaveBeenCalledTimes(1)
+  })
+
+  it('rejects clearing the VAT number while the company stays registered', async () => {
+    enqueue({
+      data: {
+        entity_type: 'aktiebolag',
+        vat_registered: true,
+        vat_number: 'SE556012579001',
+        moms_period: 'quarterly',
+        onboarding_complete: true,
+      },
+    })
+
+    // Explicit null is a clear, not an omission: it must not fall back to the
+    // stored number during validation.
+    const response = await PUT(createMockRequest('/api/settings', {
+      method: 'PUT',
+      body: { vat_number: null },
+    }), { params: Promise.resolve({}) })
+    const { status, body } = await parseJsonResponse<{ error: string }>(response)
+
+    expect(status).toBe(400)
+    expect(body.error).toContain('Momsregistreringsnummer')
+    expect(supabase.from).toHaveBeenCalledTimes(1)
+  })
+
+  it('rejects clearing the moms period while the company stays registered', async () => {
+    enqueue({
+      data: {
+        entity_type: 'aktiebolag',
+        vat_registered: true,
+        vat_number: 'SE556012579001',
+        moms_period: 'quarterly',
+        onboarding_complete: true,
+      },
+    })
+
+    const response = await PUT(createMockRequest('/api/settings', {
+      method: 'PUT',
+      body: { moms_period: null },
+    }), { params: Promise.resolve({}) })
+    const { status, body } = await parseJsonResponse<{ error: string }>(response)
+
+    expect(status).toBe(400)
+    expect(body.error).toContain('Momsperiod')
+    expect(supabase.from).toHaveBeenCalledTimes(1)
+  })
+
+  it('rejects enabling periodisk sammanställning while the VAT registration is incomplete', async () => {
+    enqueue({
+      data: {
+        entity_type: 'aktiebolag',
+        vat_registered: true,
+        vat_number: null,
+        moms_period: 'quarterly',
+        vat_has_eu_trade: true,
+        onboarding_complete: true,
+      },
+    })
+
+    const response = await PUT(createMockRequest('/api/settings', {
+      method: 'PUT',
+      body: { periodisk_sammanstallning_enabled: true },
+    }), { params: Promise.resolve({}) })
+    const { status, body } = await parseJsonResponse<{ error: string }>(response)
+
+    expect(status).toBe(400)
+    expect(body.error).toContain('Momsregistreringsnummer')
+    expect(supabase.from).toHaveBeenCalledTimes(1)
+  })
+
+  it('allows an unrelated save when a stored 40m/period conflict already exists', async () => {
+    // Stored state violates the 40m-monthly rule; a save that touches neither
+    // group must still go through.
+    enqueueMany([
+      {
+        data: {
+          entity_type: 'aktiebolag',
+          vat_registered: true,
+          vat_number: 'SE556012579001',
+          moms_period: 'quarterly',
+          vat_taxable_base_over_40m: true,
+          onboarding_complete: true,
+        },
+      },
+      { data: { id: 's1', company_name: 'Testbolaget AB' } }, // update
+      { data: null, count: 5 },                               // deadlines count
+    ])
+
+    const response = await PUT(createMockRequest('/api/settings', {
+      method: 'PUT',
+      body: { company_name: 'Testbolaget AB' },
+    }), { params: Promise.resolve({}) })
+    const { status } = await parseJsonResponse(response)
+
+    expect(status).toBe(200)
+  })
 })

app/api/settings/route.ts

@@ -182,14 +182,31 @@ export const PUT = withRouteContext(
       body.employer_seasonal = false
     }
 
-    // Validate: VAT-registered must have VAT number (ML 11 kap. 8§) and moms period (SFL 26 kap.)
+    // Validate: VAT-registered must have VAT number (ML 17 kap. 24 §, the
+    // invoice needs it) and moms period (SFL 26 kap.).
+    // Each cross-field check runs only when the request touches a field in its
+    // group: a partial save of unrelated settings (e.g. the invoice bank-details
+    // dialog) must not be rejected for a pre-existing inconsistency it cannot
+    // fix from that surface. Explicit null counts as touched, it clears a value,
+    // so it must not fall back to the stored one during validation.
+    // PS/EU-trade edits are in the completeness group: enabling the EU sales
+    // list on an incomplete VAT registration must keep failing like it did
+    // when the check ran on every save.
     const effectiveVatRegistered = body.vat_registered ?? oldSettings?.vat_registered
-    const effectiveMomsPeriod = body.moms_period ?? oldSettings?.moms_period
-    if (effectiveVatRegistered === true) {
-      const effectiveVatNumber = body.vat_number ?? oldSettings?.vat_number
+    const effectiveMomsPeriod =
+      body.moms_period !== undefined ? body.moms_period : oldSettings?.moms_period
+    const touchesVatCompleteness =
+      body.vat_registered !== undefined ||
+      body.vat_number !== undefined ||
+      body.moms_period !== undefined ||
+      body.vat_has_eu_trade !== undefined ||
+      body.periodisk_sammanstallning_enabled !== undefined
+    if (touchesVatCompleteness && effectiveVatRegistered === true) {
+      const effectiveVatNumber =
+        body.vat_number !== undefined ? body.vat_number : oldSettings?.vat_number
       if (!effectiveVatNumber) {
         return NextResponse.json(
-          { error: 'Momsregistreringsnummer krävs när företaget är momsregistrerat (ML 11 kap. 8§)' },
+          { error: 'Momsregistreringsnummer krävs när företaget är momsregistrerat (ML 17 kap. 24 §)' },
           { status: 400 }
         )
       }
@@ -201,21 +218,34 @@ export const PUT = withRouteContext(
       }
     }
 
+    const touchesVat40m =
+      body.vat_registered !== undefined ||
+      body.vat_taxable_base_over_40m !== undefined ||
+      body.moms_period !== undefined
     const effectiveVatTaxableBaseOver40m =
       body.vat_taxable_base_over_40m ?? oldSettings?.vat_taxable_base_over_40m ?? false
-    if (effectiveVatRegistered && effectiveVatTaxableBaseOver40m && effectiveMomsPeriod !== 'monthly') {
+    if (
+      touchesVat40m &&
+      effectiveVatRegistered &&
+      effectiveVatTaxableBaseOver40m &&
+      effectiveMomsPeriod !== 'monthly'
+    ) {
       return NextResponse.json(
         { error: 'Företag med beskattningsunderlag över 40 miljoner kronor måste redovisa moms varje månad.' },
         { status: 400 },
       )
     }
 
+    const touchesPs =
+      body.periodisk_sammanstallning_enabled !== undefined ||
+      body.vat_registered !== undefined ||
+      body.vat_has_eu_trade !== undefined
     const effectivePsEnabled =
       body.periodisk_sammanstallning_enabled ??
       oldSettings?.periodisk_sammanstallning_enabled ??
       false
     const effectiveEuTrade = body.vat_has_eu_trade ?? oldSettings?.vat_has_eu_trade ?? false
-    if (effectivePsEnabled && (!effectiveVatRegistered || !effectiveEuTrade)) {
+    if (touchesPs && effectivePsEnabled && (!effectiveVatRegistered || !effectiveEuTrade)) {
       return NextResponse.json(
         { error: 'Periodisk sammanställning kräver momsregistrering och EU-handel.' },
         { status: 400 },

app/api/v1/companies/[companyId]/invoices/[id]/mark-sent/__tests__/route.test.ts

@@ -255,6 +255,38 @@ describe('POST /api/v1/companies/:companyId/invoices/:id/mark-sent', () => {
     },
   )
 
+  it('rejects issuance when the registered company has no VAT number', async () => {
+    mockServiceClient.mockReturnValue(
+      makeFlexibleSupabase({
+        company_members: { data: { company_id: COMPANY_ID, role: 'owner' }, error: null },
+        invoices: { data: DRAFT_INVOICE, error: null },
+        company_settings: {
+          data: {
+            accounting_method: 'accrual',
+            entity_type: 'enskild_firma',
+            bankgiro: '123-4567',
+            vat_registered: true,
+            vat_number: null,
+          },
+          error: null,
+        },
+      }),
+    )
+
+    const res = await markSent(
+      makeMarkSentRequest(
+        `https://x.test/api/v1/companies/${COMPANY_ID}/invoices/${INVOICE_ID}/mark-sent`,
+      ),
+      detailParams(COMPANY_ID, INVOICE_ID),
+    )
+
+    expect(res.status).toBe(400)
+    const body = await res.json()
+    expect(body.error.code).toBe('INVOICE_SEND_VAT_NUMBER_MISSING')
+    expect(mockEnsureInvoiceNumber).not.toHaveBeenCalled()
+    expect(mockCreateJournalEntry).not.toHaveBeenCalled()
+  })
+
   it('rejects delivery notes with VALIDATION_ERROR (regardless of status)', async () => {
     // Critical: the delivery-note guard must run BEFORE the status check
     // so a sent delivery note still returns 400 (per the documented

app/api/v1/companies/[companyId]/invoices/[id]/mark-sent/route.ts

@@ -51,6 +51,7 @@ import { recordManualInvoiceDelivery } from '@/lib/invoices/invoice-deliveries'
 import {
   hasRequiredInvoicePaymentAccount,
 } from '@/lib/invoices/payment-accounts'
+import { hasRequiredSellerVatNumber } from '@/lib/invoices/seller-vat-number'
 import { eventBus } from '@/lib/events'
 import type { CompanySettings, EntityType, Invoice } from '@/types'
 
@@ -217,7 +218,7 @@ export const POST = withApiV1<{ params: Promise<{ companyId: string; id: string
     // decision, payable invoices need a currency-matching account.
     const { data: settings, error: settingsError } = await ctx.supabase
       .from('company_settings')
-      .select('accounting_method, defer_invoice_booking, entity_type, invoice_payment_accounts, bank_name, clearing_number, account_number, bankgiro, plusgiro, swish, iban, bic')
+      .select('accounting_method, defer_invoice_booking, entity_type, invoice_payment_accounts, bank_name, clearing_number, account_number, bankgiro, plusgiro, swish, iban, bic, vat_registered, vat_number')
       .eq('company_id', ctx.companyId!)
       .maybeSingle()
     if (settingsError || !settings) {
@@ -238,6 +239,11 @@ export const POST = withApiV1<{ params: Promise<{ companyId: string; id: string
         details: { currency: typed.currency },
       })
     }
+    if (!hasRequiredSellerVatNumber(companySettings, typed)) {
+      return v1ErrorResponseFromCode('INVOICE_SEND_VAT_NUMBER_MISSING', ctx.log, {
+        requestId: ctx.requestId,
+      })
+    }
     const accountingMethod = companySettings.accounting_method ?? 'accrual'
     const entityType = (companySettings.entity_type ?? 'enskild_firma') as EntityType
     const isRealInvoice = !typed.document_type || typed.document_type === 'invoice'

app/api/v1/companies/[companyId]/invoices/[id]/send/__tests__/route.test.ts

@@ -353,6 +353,30 @@ describe('POST /api/v1/companies/:companyId/invoices/:id/send', () => {
     },
   )
 
+  it('rejects issuance when the registered company has no VAT number', async () => {
+    mockServiceClient.mockReturnValue(
+      makeFlexibleSupabase({
+        company_members: { data: { company_id: COMPANY_ID, role: 'owner' }, error: null },
+        invoices: { data: DRAFT_INVOICE, error: null },
+        company_settings: {
+          data: { ...COMPANY_SETTINGS, vat_registered: true, vat_number: null },
+          error: null,
+        },
+      }),
+    )
+
+    const res = await sendInvoice(
+      makeRequest(`https://x.test/api/v1/companies/${COMPANY_ID}/invoices/${INVOICE_ID}/send`),
+      detailParams(COMPANY_ID, INVOICE_ID),
+    )
+
+    expect(res.status).toBe(400)
+    const body = await res.json()
+    expect(body.error.code).toBe('INVOICE_SEND_VAT_NUMBER_MISSING')
+    expect(mockEnsureInvoiceNumber).not.toHaveBeenCalled()
+    expect(mockSendEmail).not.toHaveBeenCalled()
+  })
+
   it('returns VALIDATION_ERROR for malformed JSON', async () => {
     mockServiceClient.mockReturnValue(
       makeFlexibleSupabase({

app/api/v1/companies/[companyId]/invoices/[id]/send/route.ts

@@ -78,6 +78,7 @@ import {
   hasRequiredInvoicePaymentAccount,
   invoiceRequiresPaymentAccount,
 } from '@/lib/invoices/payment-accounts'
+import { hasRequiredSellerVatNumber } from '@/lib/invoices/seller-vat-number'
 import { eventBus } from '@/lib/events'
 import { guardSandbox } from '@/lib/sandbox/guard'
 import { requireCapability } from '@/lib/entitlements/has-capability'
@@ -357,6 +358,12 @@ export const POST = withApiV1<{ params: Promise<{ companyId: string; id: string
       })
     }
 
+    if (!hasRequiredSellerVatNumber(settings, typed)) {
+      return v1ErrorResponseFromCode('INVOICE_SEND_VAT_NUMBER_MISSING', ctx.log, {
+        requestId: ctx.requestId,
+      })
+    }
+
     const hasAdditionalRecipients =
       (bodyResult.data.additional_cc?.length ?? 0) > 0
       || (bodyResult.data.additional_bcc?.length ?? 0) > 0