DATEV Import Failed? The 7 Most Common EXTF Errors and How to Fix Them

It is the month-end classic: the accounting batch is exported, the email to your tax advisor’s office is sent – and the next morning the reply arrives: “The file won’t import into DATEV.” Now the search begins. Was it the header? A date? One booking row out of 4,000?

The good news: DATEV imports rarely fail for exotic reasons. In practice, it is almost always one of the same seven structural errors. If you know them, you find the cause in minutes instead of hours – and if you validate your export before sending it, that email from the accounting office never arrives in the first place.

How an EXTF file is structured – and why it is so unforgiving

The EXTF format is a strictly specified CSV/ASCII structure: line 1 carries the header with version indicators, consultant and client numbers plus the fiscal year, line 2 holds the column headings, and the booking rows follow. DATEV Rechnungswesen does not read the file “generously” – it reads it against rules. If a mandatory field deviates from the specification, the import aborts or rows are discarded, often with an error message that names only a line number, not a cause.

That is exactly why a systematic look at the typical breaking points pays off.

The 7 most common import errors at a glance

#	Error	Typical symptom	Fix
1	Damaged header (line 1 without a valid “EXTF” identifier)	Import aborts immediately	Regenerate the header from the source system, never edit it by hand
2	Wrong date format (document date not DDMM)	“Invalid date” from row X	Check leading zeros: 1 May is 0105, not 105
3	Decimal point instead of comma	Amounts shifted by a factor of 100 or rejected	Export amounts with a comma as the decimal separator
4	Invalid debit/credit flag	Rows are discarded	Only S (debit) and H (credit) are allowed
5	Missing quotation marks around text fields	Column shift, “too many fields”	Posting texts containing semicolons belong inside "…"
6	Wrong field count per row	Structural error on import	Every row must match the column count of the heading row exactly
7	Account outside the expected range	Warnings or mispostings	Reconcile ledger accounts against the chart of accounts (SKR 03/04)

The order is not random: header and format errors (1–3) block the import entirely, field errors (4–6) cost individual rows, and account errors (7) often only surface at the accounting office.

The Excel trap: the main source of errors 2, 3 and 5

Many of these problems are not created in the source system but afterwards – during a “quick look” in Excel. Excel happily opens an EXTF file, but saves it back by its own rules: leading zeros disappear (document date 0105 becomes 105), amounts get reinterpreted, and quotes and semicolons are written back differently from what DATEV expects.

The rule is simple: viewing yes, saving no. If you need to correct something, use a plain text editor – or fix the data in the source system and regenerate the export.

Check in three minutes instead of waiting three days

The fastest way to test all seven error classes at once is a structured pre-send check. That is exactly what our free DATEV Export Validator does: select the file, read the validation report, done. The tool analyses the header, field counts, date and amount formats and debit/credit flags – entirely locally in your browser, so your accounting data never leaves your device.

One important caveat: a green result confirms the structure, not the substance. Whether revenue lands on the right account or which tax key applies remains a professional judgement – no tool replaces your tax advisor there.

Why clean batches are more than a convenience

A batch that imports on the first attempt saves more than one correction loop. It is also the foundation of a clean month-end close: German GoBD rules require bookings to be immutable once locked – every late fix to an already delivered batch produces reversals and queries. Our article on the GoBD monthly lock explains that process in detail. And with mandatory e-invoicing arriving in 2026, the share of structured documents keeps rising – and the tolerance for hand-crafted exports keeps falling.

Conclusion: finding errors is good, preventing them is better

The seven error classes above cover the vast majority of failed DATEV imports. With a pre-send check – for example with the free DATEV Export Validator – they become a non-event.

The most sustainable route, however, bypasses manual exports altogether: KudTax generates EXTF files directly from your shop and marketplace data – with a correct header, valid formats and reconciled accounts, built to pass validation by design. Invoices and transactions from Amazon, eBay, Shopify & co. are matched automatically and handed to your accounting office ready to book. See all features.