DATEV booking batch (EXTF): format, fields and import

When a German tax advisor (Steuerberater) asks for your bookings "as a DATEV batch", they mean one specific file: the Buchungsstapel in DATEV format. A spreadsheet of your expenses is not the same thing, because the firm would have to map it column by column. A real booking batch imports directly.

What the DATEV booking batch is

The DATEV format is a CSV file with a fixed layout that DATEV documents for data exchange with other software. There are several format categories, for example for master data or customers and suppliers. Bookings use category 21, "Buchungsstapel". Accounting firms import these files into DATEV Rechnungswesen (for example Kanzlei-Rechnungswesen) via Bestand → Importieren → Stapelverarbeitung (DATEV help document 1034038, as of October 2026).

Why it matters to you: instead of typing in your receipts, the firm only reviews bookings that are already pre-assigned to accounts. That saves them time, and time is a real cost driver on an accounting firm's bill.

How the file is structured

According to DATEV's format description, the file name starts with EXTF_ and ends in .csv. Inside the file (DATEV Developer Portal, as of October 2026):

• Line 1, the header: starts with "EXTF";700;21;"Buchungsstapel";13, that is the marker, header version, format category, format name and format version. It continues with the creation date, the start of the fiscal year (Wirtschaftsjahr), the account number length and the booking period, among others.
• Line 2: the column names.
• From line 3: one booking per line.
• Fields are separated by semicolons, lines end with CR/LF, text fields are quoted and decimals use a comma.

The fields that matter most in a booking line:

Tip: The document date has no year. DATEV books into the fiscal year named in the header, so send one file per year. Otherwise January receipts from the next year end up in the wrong one.

Common import mistakes

• Opening and saving the file in Excel. DATEV notes that this can change the structure or header, after which the file is no longer recognised as DATEV format. Re-export instead.
• Negative amounts instead of a debit/credit flag. The amount is always positive; the direction lives in the flag.
• The wrong chart of accounts. SKR03 and SKR04 use different account numbers. Ask the firm which one applies to you.
• Document numbers restarting at 1 with every export. Two deliveries then share the same numbers. A sequence that continues across exports avoids the clash.
• Business meals without a split. Business entertainment (Bewirtung) is only 70 % deductible as a business expense (§ 4 (5) sentence 1 no. 2 EStG, as of October 2026), so the firm books it to two accounts.

How Bonro creates the booking batch

Bonro turns your photographed receipts into a booking batch in DATEV format: a header with version 700 and category 21, column names on line 2, one booking per receipt. Account and contra account come from SKR03 (26 expense categories, for example 4930 office supplies), the tax key from the VAT rate. The document number in Belegfeld 1 continues across exports (R000001, R000002 …) instead of restarting each time. Business meals are split 70/30 over two lines, both carrying the tax key so the full input VAT is captured. The adviser and client numbers stay empty; the firm assigns the batch to your client file on import.

You can check and correct every field before exporting. The DATEV export is part of the Pro plan; see Bonro's pricing for details.