AccountingFree Tool

DATEV Export Validator

Free online tool to validate DATEV EXTF files (ASCII/CSV). Check headers, data row syntax, and field formats before sending to your tax advisor.

DATEV EXTF CSV Validator

Validate DATEV EXTF header structure & transaction rows in real-time

Overall Status
Errors found
Rows Checked
7
Errors
2
Warnings
2

Line Inspection Protocol

LineStatusFieldMessage / Finding
#1VALIDHEADER_EXTFValid EXTF header detected (Format version 700, Category: Buchungsstapel)"EXTF";700;21;"Buchungsstapel";12;20260101;;"KTX";"KTX Softw...
#2VALIDHEADER_FIELDSColumn headers parsed (8 field names)."Umsatz";"Soll/Haben-Kennzeichen";"Konto";"Gegenkonto";"BU-S...
#3VALIDZeile OKRow syntax valid (Account 8400, Offset 1200, Amount 1500,00 S)."1500,00";"S";"8400";"1200";;"0105";"INV-2026-001";"Erlöse 19% USt"
#4VALIDZeile OKRow syntax valid (Account 4900, Offset 1200, Amount 250,50 H)."250,50";"H";"4900";"1200";;"1005";"RE-8812";"Büromaterial"
#5ERRORUmsatzInvalid amount 'invalid_amount'. Numeric value expected."invalid_amount";"X";"120";"ABC";;"9999";"ERR-001";"Testfehler Zeile"
#5ERRORSoll/HabenInvalid S/H indicator 'X'. Only 'S' or 'H' allowed."invalid_amount";"X";"120";"ABC";;"9999";"ERR-001";"Testfehler Zeile"
#5WARNINGKontoUnusual account number format '120'. Standardly 4 to 8 digits."invalid_amount";"X";"120";"ABC";;"9999";"ERR-001";"Testfehler Zeile"
#5WARNINGGegenkontoUnusual offset account format 'ABC'."invalid_amount";"X";"120";"ABC";;"9999";"ERR-001";"Testfehler Zeile"
#6VALIDZeile OKRow syntax valid (Account 8400, Offset 1200, Amount 99,00 S)."99,00";"S";"8400";"1200";;"1505";"INV-2026-002";"Beratungsleistung"
#7VALIDZeile OKRow syntax valid (Account 8400, Offset 1400, Amount 450,00 S)."450,00";"S";"8400";"1400";;"2005";"INV-2026-003";"Warenverkauf Online"

Format errors like these almost always come from manual exports. KudTax writes error-free EXTF files directly from your shop and marketplace data.

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GUIDE & INSIGHTS

Guide: DATEV EXTF Header & Row Validation Rules

DATEV imports rarely fail because of what you booked. They fail because of how the file is shaped. EXTF is the official standard for moving transaction data between accounting software and DATEV Accounting systems, and it tolerates no deviation. Every valid file has three blocks: the header in line 1, the column captions in line 2, and the actual journal lines from line 3 onwards. The DATEV Export Validator reads your file in exactly that order, entirely inside your browser.

The header line, field by field

The header is a single semicolon-separated line. Here is the sample line shipped with the tool, broken apart:

Pos.ValueMeaning
1"EXTF"Format identifier — if it is missing, the import aborts immediately
2700DATEV format version number
321Format category (21 = journal batch)
4"Buchungsstapel"Plain-text name of the category
512Format version within the category
620260101Creation date, in YYYYMMDD
7(empty)Not populated on export
8"KTX"Origin, i.e. the generating system
9"KTX Software System"Exported by
10(empty)Imported by
1110001Consultant number
1299999Client number
1320260101Start of the fiscal year
144General ledger account length

Later positions carry the date range, the batch description and the lock (Festschreibung) flag. From the header the validator reads the EXTF identifier, the version number, the category name, the creation date and the field count, then reports line 1 as valid or broken.

Five failures that stop an import

  1. No EXTF marker in line 1. Usually the file was opened and re-saved in Excel, which strips the quoting or the header line entirely. Fix: re-export from the source system and never round-trip through a spreadsheet.
  2. Thousands separators in the amount. "1.500,00" is flagged as an invalid amount. The correct form is "1500,00" — decimal comma, no grouping, no currency symbol. Direction is expressed by the S/H flag, not by a minus sign.
  3. Invalid debit/credit indicator. Only S (debit) and H (credit) are accepted. English-language systems often emit D/C, and shop plugins sometimes leave the field empty. Both are hard errors.
  4. Account or offset account out of shape. Four to eight digits are expected; 120 (leading zero lost) or ABC raise a warning. The digit length must match the account length declared in position 14, otherwise DATEV creates unwanted new accounts on import.
  5. Wrong document date format. DDMM (0105), DD.MM.YYYY or YYYYMMDD are accepted. An ISO date such as 2026-01-05 is flagged. Again, spreadsheets silently drop the leading zero and turn 0105 into 105.

Errors block the import; warnings mark unusual but technically permitted values. Clear both before handing the batch over.

After the file passes

A syntactically clean file is not automatically a correctly booked file. The validator says nothing about account mapping, tax keys or period cut-off — it is a format check for orientation and no substitute for advice from your tax advisor. If you hand over batches monthly, plan for locking too, which we cover in how the GoBD monthly lock works, because corrections to a locked batch are painful. And if you are reworking your outgoing invoices at the same time, read our overview of e-invoicing in 2026 with XRechnung and ZUGFeRD — structured invoice data and clean journal batches increasingly go hand in hand.

FREQUENTLY ASKED QUESTIONS

Questions & Answers

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