fix: address user feedback — RC preview, bank sync lookback, CSV import robustness (#233)

Three confirmed issues from user feedback:

1. Reverse charge preview now uses per-item VAT rates and correct accounts
   (2645/2647, 2614/2624/2634) instead of hardcoded 25%/2614
2. Bank sync uses 90-day lookback on first sync (when last_synced_at is null)
   instead of hardcoded 7 days for all syncs
3. Bank file import improvements:
   - Shared date normalizer supporting DD.MM.YYYY, DD/MM/YYYY, YYYYMMDD
   - Silent row skips now reported with reason in issues[]
   - Decimal separator mismatch detection in generic CSV
   - Swedish error message with format diagnostics on detection failure
   - Date format selector in column mapping UI

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/api/extensions/enable-banking/sync/cron/route.ts

@@ -132,7 +132,13 @@ export async function GET(request: Request) {
       }
 
       const toDate = new Date().toISOString().split('T')[0]
-      const fromDate = new Date(Date.now() - 7 * 24 * 60 * 60 * 1000)
+      // First sync: 90-day lookback (PSD2 max). Subsequent: 7-day window.
+      const isFirstSync = !connection.last_synced_at
+      const lookbackDays = isFirstSync ? 90 : 7
+      if (isFirstSync) {
+        console.log(`[bank-sync-cron] First sync for connection ${connection.id}, using ${lookbackDays}-day lookback`)
+      }
+      const fromDate = new Date(Date.now() - lookbackDays * 24 * 60 * 60 * 1000)
         .toISOString()
         .split('T')[0]
 

components/import/BankFileColumnMappingStep.tsx

@@ -44,6 +44,7 @@ export default function BankFileColumnMappingStep({
   const [balanceCol, setBalanceCol] = useState<number>(-1)
   const [delimiter, setDelimiter] = useState<string>(',')
   const [decimalSep, setDecimalSep] = useState<',' | '.'>(',')
+  const [dateFormat, setDateFormat] = useState<string>('YYYY-MM-DD')
 
   const isValid = dateCol >= 0 && descCol >= 0 && amountCol >= 0
 
@@ -58,7 +59,7 @@ export default function BankFileColumnMappingStep({
       delimiter,
       decimal_separator: decimalSep,
       skip_rows: 1, // Skip header
-      date_format: 'YYYY-MM-DD',
+      date_format: dateFormat,
     }
     onConfirm(mapping)
   }
@@ -78,8 +79,8 @@ export default function BankFileColumnMappingStep({
           </CardDescription>
         </CardHeader>
         <CardContent className="space-y-6">
-          {/* Delimiter and decimal settings */}
-          <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
+          {/* Delimiter, decimal, and date format settings */}
+          <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
             <div className="space-y-2">
               <Label>Avgränsare</Label>
               <Select value={delimiter} onValueChange={(v) => { if (v) setDelimiter(v) }}>
@@ -105,6 +106,20 @@ export default function BankFileColumnMappingStep({
                 </SelectContent>
               </Select>
             </div>
+            <div className="space-y-2">
+              <Label>Datumformat</Label>
+              <Select value={dateFormat} onValueChange={(v) => { if (v) setDateFormat(v) }}>
+                <SelectTrigger>
+                  <SelectValue />
+                </SelectTrigger>
+                <SelectContent>
+                  <SelectItem value="YYYY-MM-DD">YYYY-MM-DD</SelectItem>
+                  <SelectItem value="DD.MM.YYYY">DD.MM.YYYY</SelectItem>
+                  <SelectItem value="DD/MM/YYYY">DD/MM/YYYY</SelectItem>
+                  <SelectItem value="YYYYMMDD">YYYYMMDD</SelectItem>
+                </SelectContent>
+              </Select>
+            </div>
           </div>
 
           {/* Required column mappings */}

components/suppliers/SupplierInvoiceReviewContent.tsx

@@ -40,12 +40,19 @@ interface JournalPreviewLine {
   credit: number
 }
 
+function getOutputVatAccount(rate: number): string {
+  if (rate === 0.12) return '2624'
+  if (rate === 0.06) return '2634'
+  return '2614'
+}
+
 function buildJournalPreview(
   items: ReviewLineItem[],
   subtotal: number,
   totalVat: number,
   total: number,
   reverseCharge: boolean,
+  supplierType?: string,
 ): JournalPreviewLine[] {
   const lines: JournalPreviewLine[] = []
 
@@ -67,21 +74,35 @@ function buildJournalPreview(
   }
 
   if (reverseCharge) {
-    // EU reverse charge: fiktiv moms
-    const vatRate = 0.25
-    const fiktivVat = Math.round(subtotal * vatRate * 100) / 100
-    lines.push({
-      account_number: '2645',
-      description: 'Beräknad ingående moms',
-      debit: fiktivVat,
-      credit: 0,
-    })
-    lines.push({
-      account_number: '2614',
-      description: 'Utgående moms omvänd',
-      debit: 0,
-      credit: fiktivVat,
-    })
+    // Reverse charge: fiktiv moms per VAT rate (matches engine groupVatByRate logic)
+    const isDomesticRC = supplierType === 'swedish_business'
+    const inputAccount = isDomesticRC ? '2647' : '2645'
+
+    const vatByRate = new Map<number, number>()
+    for (const item of items) {
+      if (item.vat_rate > 0) {
+        const current = vatByRate.get(item.vat_rate) || 0
+        vatByRate.set(item.vat_rate, current + Math.round(item.amount * 100) / 100)
+      }
+    }
+
+    for (const [rate, netAmount] of vatByRate) {
+      const fiktivVat = Math.round(netAmount * rate * 100) / 100
+      const outputAccount = getOutputVatAccount(rate)
+      lines.push({
+        account_number: inputAccount,
+        description: inputAccount,
+        debit: fiktivVat,
+        credit: 0,
+      })
+      lines.push({
+        account_number: outputAccount,
+        description: outputAccount,
+        debit: 0,
+        credit: fiktivVat,
+      })
+    }
+
     // Credit: 2440 at subtotal (no real VAT for reverse charge)
     lines.push({
       account_number: '2440',
@@ -113,8 +134,11 @@ function buildJournalPreview(
 const ACCOUNT_LABELS: Record<string, string> = {
   '2440': 'Leverantörsskulder',
   '2641': 'Ingående moms',
-  '2645': 'Beräknad ingående moms',
-  '2614': 'Utg. moms omvänd skattskyldighet',
+  '2645': 'Beräknad ing. moms förvärv utlandet',
+  '2647': 'Beräknad ing. moms omvänd i Sverige',
+  '2614': 'Utg. moms omvänd 25%',
+  '2624': 'Utg. moms omvänd 12%',
+  '2634': 'Utg. moms omvänd 6%',
 }
 
 export function SupplierInvoiceReviewContent({
@@ -132,7 +156,7 @@ export function SupplierInvoiceReviewContent({
   totalVat,
   total,
 }: SupplierInvoiceReviewContentProps) {
-  const journalLines = buildJournalPreview(items, subtotal, totalVat, total, reverseCharge)
+  const journalLines = buildJournalPreview(items, subtotal, totalVat, total, reverseCharge, supplier.supplier_type)
   const totalDebit = journalLines.reduce((sum, l) => sum + l.debit, 0)
   const totalCredit = journalLines.reduce((sum, l) => sum + l.credit, 0)
 

lib/bookkeeping/client-account-names.ts

@@ -22,9 +22,12 @@ const ACCOUNT_NAMES: Record<string, string> = {
   '2611': 'Utg. moms 25%',
   '2621': 'Utg. moms 12%',
   '2631': 'Utg. moms 6%',
-  '2614': 'Utg. moms omvänd',
+  '2614': 'Utg. moms omvänd 25%',
+  '2624': 'Utg. moms omvänd 12%',
+  '2634': 'Utg. moms omvänd 6%',
   '2641': 'Ing. moms',
-  '2645': 'Beräknad ing. moms',
+  '2645': 'Beräknad ing. moms förvärv utlandet',
+  '2647': 'Beräknad ing. moms omvänd i Sverige',
   '2731': 'Arbetsgivaravgifter',
   '2893': 'Skuld till ägare',
 

lib/import/bank-file/__tests__/date-utils.test.ts

@@ -0,0 +1,92 @@
+import { describe, it, expect } from 'vitest'
+import { normalizeDate } from '../date-utils'
+
+describe('normalizeDate', () => {
+  // Pass-through for canonical format
+  it('passes through YYYY-MM-DD', () => {
+    expect(normalizeDate('2024-01-15')).toBe('2024-01-15')
+    expect(normalizeDate('2026-12-31')).toBe('2026-12-31')
+  })
+
+  // European dot format
+  it('normalizes DD.MM.YYYY', () => {
+    expect(normalizeDate('15.01.2024')).toBe('2024-01-15')
+    expect(normalizeDate('31.12.2026')).toBe('2026-12-31')
+  })
+
+  it('normalizes D.M.YYYY (single-digit day/month)', () => {
+    expect(normalizeDate('5.1.2024')).toBe('2024-01-05')
+    expect(normalizeDate('9.3.2025')).toBe('2025-03-09')
+  })
+
+  // European slash format
+  it('normalizes DD/MM/YYYY', () => {
+    expect(normalizeDate('15/01/2024')).toBe('2024-01-15')
+    expect(normalizeDate('31/12/2026')).toBe('2026-12-31')
+  })
+
+  it('normalizes D/M/YYYY (single-digit)', () => {
+    expect(normalizeDate('5/1/2024')).toBe('2024-01-05')
+  })
+
+  // US format with hint
+  it('normalizes MM/DD/YYYY when hint is provided', () => {
+    expect(normalizeDate('01/15/2024', 'MM/DD/YYYY')).toBe('2024-01-15')
+    expect(normalizeDate('12/31/2026', 'MM/DD/YYYY')).toBe('2026-12-31')
+  })
+
+  // Compact format
+  it('normalizes YYYYMMDD', () => {
+    expect(normalizeDate('20240115')).toBe('2024-01-15')
+    expect(normalizeDate('20261231')).toBe('2026-12-31')
+  })
+
+  // Slash year-first format
+  it('normalizes YYYY/MM/DD', () => {
+    expect(normalizeDate('2024/01/15')).toBe('2024-01-15')
+    expect(normalizeDate('2026/12/31')).toBe('2026-12-31')
+  })
+
+  // Whitespace handling
+  it('trims whitespace', () => {
+    expect(normalizeDate(' 2024-01-15 ')).toBe('2024-01-15')
+    expect(normalizeDate('  15.01.2024  ')).toBe('2024-01-15')
+  })
+
+  // Invalid dates
+  it('returns null for empty/null/undefined', () => {
+    expect(normalizeDate('')).toBeNull()
+    expect(normalizeDate(null)).toBeNull()
+    expect(normalizeDate(undefined)).toBeNull()
+    expect(normalizeDate('   ')).toBeNull()
+  })
+
+  it('returns null for unrecognized formats', () => {
+    expect(normalizeDate('Jan 15, 2024')).toBeNull()
+    expect(normalizeDate('15-Jan-2024')).toBeNull()
+    expect(normalizeDate('abc')).toBeNull()
+    expect(normalizeDate('2024')).toBeNull()
+  })
+
+  it('returns null for invalid month', () => {
+    expect(normalizeDate('2024-13-01')).toBeNull()
+    expect(normalizeDate('2024-00-01')).toBeNull()
+  })
+
+  it('returns null for invalid day', () => {
+    expect(normalizeDate('2024-02-30')).toBeNull() // Feb 30 doesn't exist
+    expect(normalizeDate('2024-04-31')).toBeNull() // Apr has 30 days
+    expect(normalizeDate('2024-01-32')).toBeNull()
+    expect(normalizeDate('2024-01-00')).toBeNull()
+  })
+
+  it('handles leap year correctly', () => {
+    expect(normalizeDate('2024-02-29')).toBe('2024-02-29') // 2024 is leap year
+    expect(normalizeDate('2023-02-29')).toBeNull() // 2023 is not
+  })
+
+  it('returns null for years out of range', () => {
+    expect(normalizeDate('1899-01-01')).toBeNull()
+    expect(normalizeDate('2101-01-01')).toBeNull()
+  })
+})

lib/import/bank-file/__tests__/parser.test.ts

@@ -1151,7 +1151,7 @@ describe('parseBankFile — explicit format override', () => {
     expect(result.format_name).toBe('Unknown')
     expect(result.transactions).toHaveLength(0)
     expect(result.issues).toHaveLength(1)
-    expect(result.issues[0].message).toContain('Could not auto-detect')
+    expect(result.issues[0].message).toContain('Kunde inte identifiera bankformat')
   })
 
   it('can force generic_csv format by explicit ID', () => {

lib/import/bank-file/date-utils.ts

@@ -0,0 +1,79 @@
+/**
+ * Date normalization for bank file imports.
+ *
+ * Converts common Swedish/European date formats to canonical YYYY-MM-DD.
+ * Used by all bank-specific parsers and the generic CSV fallback.
+ */
+
+/**
+ * Normalize a date string to YYYY-MM-DD.
+ *
+ * Supported formats:
+ * - YYYY-MM-DD (pass-through)
+ * - YYYY/MM/DD
+ * - YYYYMMDD
+ * - DD.MM.YYYY / D.M.YYYY
+ * - DD/MM/YYYY / D/M/YYYY
+ *
+ * The `hint` parameter disambiguates DD/MM vs MM/DD when using slash separators.
+ * Default assumption is DD/MM (European convention) since this is a Swedish app.
+ *
+ * Returns the canonical YYYY-MM-DD string, or null if unparseable.
+ */
+export function normalizeDate(raw: string | undefined | null, hint?: string): string | null {
+  if (!raw) return null
+  const s = raw.trim()
+  if (!s) return null
+
+  let year: number
+  let month: number
+  let day: number
+
+  // YYYY-MM-DD
+  if (/^\d{4}-\d{2}-\d{2}$/.test(s)) {
+    const [y, m, d] = s.split('-').map(Number)
+    year = y; month = m; day = d
+
+  // YYYY/MM/DD
+  } else if (/^\d{4}\/\d{2}\/\d{2}$/.test(s)) {
+    const [y, m, d] = s.split('/').map(Number)
+    year = y; month = m; day = d
+
+  // YYYYMMDD
+  } else if (/^\d{8}$/.test(s)) {
+    year = parseInt(s.substring(0, 4), 10)
+    month = parseInt(s.substring(4, 6), 10)
+    day = parseInt(s.substring(6, 8), 10)
+
+  // DD.MM.YYYY or D.M.YYYY
+  } else if (/^\d{1,2}\.\d{1,2}\.\d{4}$/.test(s)) {
+    const parts = s.split('.').map(Number)
+    day = parts[0]; month = parts[1]; year = parts[2]
+
+  // DD/MM/YYYY or D/M/YYYY (or MM/DD/YYYY based on hint)
+  } else if (/^\d{1,2}\/\d{1,2}\/\d{4}$/.test(s)) {
+    const parts = s.split('/').map(Number)
+    if (hint === 'MM/DD/YYYY') {
+      month = parts[0]; day = parts[1]; year = parts[2]
+    } else {
+      // Default: DD/MM/YYYY (European)
+      day = parts[0]; month = parts[1]; year = parts[2]
+    }
+
+  } else {
+    return null
+  }
+
+  // Validate ranges
+  if (year < 1900 || year > 2100) return null
+  if (month < 1 || month > 12) return null
+  if (day < 1 || day > 31) return null
+
+  // Check day is valid for the given month
+  const maxDay = new Date(year, month, 0).getDate()
+  if (day > maxDay) return null
+
+  const mm = String(month).padStart(2, '0')
+  const dd = String(day).padStart(2, '0')
+  return `${year}-${mm}-${dd}`
+}

lib/import/bank-file/formats/generic-csv.ts

@@ -8,6 +8,7 @@
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue, GenericCSVColumnMapping } from '../types'
 import { prepareContent } from '../encoding'
 import { parseCSVLine } from './nordea'
+import { normalizeDate } from '../date-utils'
 
 /**
  * Parse a generic CSV with user-provided column mapping
@@ -26,6 +27,32 @@ export function parseGenericCSV(
   // Skip configured number of header/metadata rows
   const startRow = mapping.skip_rows
 
+  // Detect decimal separator mismatch by sampling amount column
+  const sampleSize = Math.min(lines.length - startRow, 20)
+  let commaPattern = 0
+  let periodPattern = 0
+  for (let s = startRow; s < startRow + sampleSize && s < lines.length; s++) {
+    const sampleLine = lines[s]?.trim()
+    if (!sampleLine) continue
+    const sampleFields = parseCSVLine(sampleLine, mapping.delimiter).map(f => f.trim().replace(/^"|"$/g, ''))
+    const amtStr = sampleFields[mapping.amount] || ''
+    if (/\d,\d{1,2}$/.test(amtStr)) commaPattern++
+    if (/\d\.\d{1,2}$/.test(amtStr)) periodPattern++
+  }
+  if (mapping.decimal_separator === ',' && periodPattern > commaPattern && periodPattern >= 3) {
+    issues.push({
+      row: 0,
+      message: 'Decimalavgränsare verkar vara punkt (.) men komma (,) är valt. Kontrollera inställningen.',
+      severity: 'warning',
+    })
+  } else if (mapping.decimal_separator === '.' && commaPattern > periodPattern && commaPattern >= 3) {
+    issues.push({
+      row: 0,
+      message: 'Decimalavgränsare verkar vara komma (,) men punkt (.) är valt. Kontrollera inställningen.',
+      severity: 'warning',
+    })
+  }
+
   for (let i = startRow; i < lines.length; i++) {
     const line = lines[i].trim()
     if (!line) continue
@@ -54,6 +81,10 @@ export function parseGenericCSV(
     const balanceStr = mapping.balance !== undefined ? fields[mapping.balance] : undefined
 
     if (!dateStr || !amountStr) {
+      const missing = []
+      if (!dateStr) missing.push('datum')
+      if (!amountStr) missing.push('belopp')
+      issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
       skippedRows++
       continue
     }
@@ -72,10 +103,10 @@ export function parseGenericCSV(
       continue
     }
 
-    // Parse date - expect YYYY-MM-DD
-    const date = dateStr.trim()
-    if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
-      issues.push({ row: i + 1, message: `Invalid date format: ${date} (expected YYYY-MM-DD)`, severity: 'warning' })
+    // Normalize date from multiple formats to YYYY-MM-DD
+    const date = normalizeDate(dateStr, mapping.date_format)
+    if (!date) {
+      issues.push({ row: i + 1, message: `Ogiltigt datumformat: ${dateStr.trim()}`, severity: 'warning' })
       skippedRows++
       continue
     }

lib/import/bank-file/formats/handelsbanken.ts

@@ -12,6 +12,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 
 function parseCommaDecimal(value: string): number {
   const cleaned = value.replace(/\s/g, '').replace(',', '.')
@@ -91,6 +92,10 @@ export const handelsbankenFormat: BankFileFormat = {
       }
 
       if (!date || !amountStr) {
+        const missing = []
+        if (!date) missing.push('datum')
+        if (!amountStr) missing.push('belopp')
+        issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
         skippedRows++
         continue
       }
@@ -102,7 +107,8 @@ export const handelsbankenFormat: BankFileFormat = {
         continue
       }
 
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -111,7 +117,7 @@ export const handelsbankenFormat: BankFileFormat = {
       const balance = balanceStr ? parseCommaDecimal(balanceStr) : null
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description: (description || 'Unknown').trim(),
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/ica-banken.ts

@@ -14,6 +14,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 
 function parseCommaDecimal(value: string): number {
   const cleaned = value.replace(/\s/g, '').replace(',', '.')
@@ -135,6 +136,10 @@ export const icaBankenFormat: BankFileFormat = {
       const balanceStr = balanceIdx >= 0 ? fields[balanceIdx] : undefined
 
       if (!date || !amountStr) {
+        const missing = []
+        if (!date) missing.push('datum')
+        if (!amountStr) missing.push('belopp')
+        issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
         skippedRows++
         continue
       }
@@ -146,7 +151,8 @@ export const icaBankenFormat: BankFileFormat = {
         continue
       }
 
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -155,7 +161,7 @@ export const icaBankenFormat: BankFileFormat = {
       const balance = balanceStr ? parseCommaDecimal(balanceStr) : null
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description: (description || 'Unknown').trim(),
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/lansforsakringar.ts

@@ -14,6 +14,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 import { parseCSVLine } from './nordea'
 
 function parseCommaDecimal(value: string): number {
@@ -123,6 +124,10 @@ export const lansforsakringarFormat: BankFileFormat = {
       const balanceStr = balanceIdx >= 0 && balanceIdx < fields.length ? fields[balanceIdx] : undefined
 
       if (!date || !amountStr) {
+        const missing = []
+        if (!date) missing.push('datum')
+        if (!amountStr) missing.push('belopp')
+        issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
         skippedRows++
         continue
       }
@@ -134,7 +139,8 @@ export const lansforsakringarFormat: BankFileFormat = {
         continue
       }
 
-      if (!DATE_RE.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -143,7 +149,7 @@ export const lansforsakringarFormat: BankFileFormat = {
       const balance = balanceStr ? parseCommaDecimal(balanceStr) : null
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description: description.trim(),
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/lunar.ts

@@ -15,6 +15,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 import { parseCSVLine } from './nordea'
 
 function parseLunarAmount(value: string): number {
@@ -90,6 +91,10 @@ export const lunarFormat: BankFileFormat = {
       const balanceStr = balanceIdx >= 0 ? fields[balanceIdx] : undefined
 
       if (!date || !amountStr) {
+        const missing = []
+        if (!date) missing.push('datum')
+        if (!amountStr) missing.push('belopp')
+        issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
         skippedRows++
         continue
       }
@@ -101,7 +106,8 @@ export const lunarFormat: BankFileFormat = {
         continue
       }
 
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -110,7 +116,7 @@ export const lunarFormat: BankFileFormat = {
       const balance = balanceStr ? parseLunarAmount(balanceStr) : null
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description: (description || 'Unknown').trim(),
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/nordea-business.ts

@@ -22,6 +22,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 
 function parseCommaDecimal(value: string): number {
   const cleaned = value.replace(/\s/g, '').replace(',', '.')
@@ -158,11 +159,8 @@ export const nordeaBusinessFormat: BankFileFormat = {
         continue
       }
 
-      // Normalize YYYY/MM/DD → YYYY-MM-DD (Format D variant)
-      const normalizedDate = date.includes('/') ? date.replace(/\//g, '-') : date
-
-      // Validate date format (YYYY-MM-DD)
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(normalizedDate)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue

lib/import/bank-file/formats/nordea.ts

@@ -13,6 +13,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 
 function parseCommaDecimal(value: string): number {
   // Swedish format: "1 234,56" or "-1 234,56"
@@ -77,8 +78,8 @@ export const nordeaFormat: BankFileFormat = {
         continue
       }
 
-      // Validate date format
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date?.trim())) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -87,7 +88,7 @@ export const nordeaFormat: BankFileFormat = {
       const balance = balanceStr ? parseCommaDecimal(balanceStr) : null
 
       transactions.push({
-        date: date.trim(),
+        date: normalizedDate,
         description: description?.trim() || 'Unknown',
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/seb.ts

@@ -10,6 +10,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 
 function parseCommaDecimal(value: string): number {
   const cleaned = value.replace(/\s/g, '').replace(',', '.')
@@ -95,7 +96,8 @@ export const sebFormat: BankFileFormat = {
         continue
       }
 
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -104,7 +106,7 @@ export const sebFormat: BankFileFormat = {
       const balance = balanceStr ? parseCommaDecimal(balanceStr) : null
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description: description.trim(),
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/skandia.ts

@@ -13,6 +13,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 
 function parseCommaDecimal(value: string): number {
   const cleaned = value.replace(/\s/g, '').replace(',', '.')
@@ -96,6 +97,10 @@ export const skandiaFormat: BankFileFormat = {
       const balanceStr = balanceIdx >= 0 ? fields[balanceIdx] : undefined
 
       if (!date || !amountStr) {
+        const missing = []
+        if (!date) missing.push('datum')
+        if (!amountStr) missing.push('belopp')
+        issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
         skippedRows++
         continue
       }
@@ -107,7 +112,8 @@ export const skandiaFormat: BankFileFormat = {
         continue
       }
 
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -116,7 +122,7 @@ export const skandiaFormat: BankFileFormat = {
       const balance = balanceStr ? parseCommaDecimal(balanceStr) : null
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description: (description || 'Unknown').trim(),
         amount,
         currency: 'SEK',

lib/import/bank-file/formats/swedbank.ts

@@ -18,6 +18,7 @@
 
 import type { BankFileFormat, BankFileParseResult, ParsedBankTransaction, BankFileParseIssue } from '../types'
 import { prepareContent } from '../encoding'
+import { normalizeDate } from '../date-utils'
 import { parseCSVLine } from './nordea'
 
 /**
@@ -137,6 +138,10 @@ export const swedbankFormat: BankFileFormat = {
       const balanceStr = balanceIdx >= 0 ? fields[balanceIdx] : undefined
 
       if (!date || !amountStr) {
+        const missing = []
+        if (!date) missing.push('datum')
+        if (!amountStr) missing.push('belopp')
+        issues.push({ row: i + 1, message: `Saknar ${missing.join(' och ')}`, severity: 'warning' })
         skippedRows++
         continue
       }
@@ -149,7 +154,8 @@ export const swedbankFormat: BankFileFormat = {
         continue
       }
 
-      if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
+      const normalizedDate = normalizeDate(date)
+      if (!normalizedDate) {
         issues.push({ row: i + 1, message: `Invalid date: ${date}`, severity: 'warning' })
         skippedRows++
         continue
@@ -163,7 +169,7 @@ export const swedbankFormat: BankFileFormat = {
         : reference || textDesc || 'Unknown'
 
       transactions.push({
-        date,
+        date: normalizedDate,
         description,
         amount,
         currency: 'SEK',

lib/import/bank-file/parser.ts

@@ -98,6 +98,11 @@ export function parseBankFile(
   } else {
     format = detectFileFormat(content, filename) || undefined
     if (!format) {
+      // Build diagnostic message listing which formats were tried
+      const tried = FORMATS
+        .filter(f => f.id !== 'generic_csv')
+        .map(f => f.name)
+      const firstLine = content.split('\n')[0]?.substring(0, 80) || ''
       return {
         format: 'generic_csv',
         format_name: 'Unknown',
@@ -106,7 +111,7 @@ export function parseBankFile(
         date_to: null,
         issues: [{
           row: 0,
-          message: 'Could not auto-detect file format. Please select your bank manually.',
+          message: `Kunde inte identifiera bankformat. Testade: ${tried.join(', ')}. Första raden: "${firstLine}". Välj bank manuellt eller använd "Annan CSV".`,
           severity: 'error',
         }],
         stats: { total_rows: 0, parsed_rows: 0, skipped_rows: 0, total_income: 0, total_expenses: 0 },