DATEV format (EXTF)

The DATEV format is a defined CSV file format used to import postings and master data into DATEV programs. Files generated by software outside DATEV carry the identifier EXTF in the header record; exports from DATEV programs carry the identifier DTVF.

Explanation

A file in DATEV format consists of three parts. The first line is the header record. According to the DATEV developer portal, it contains the identifier EXTF, header version 700 and the format category, among other things, as well as details such as advisor and client number, start of the fiscal year and length of the general ledger accounts. The second line contains the column headings. The data lines follow.

The format category determines what the file contains. Category 21 stands for the posting batch (Buchungsstapel). There are further categories for master data such as debtors and creditors. Fixed rules apply to the syntax: fields are separated by semicolons, text fields are enclosed in quotation marks, decimal numbers use a comma, and each line ends with CR/LF. The default character set is ISO-8859-1 (Windows-1252). UTF-8 works only with a byte order mark (BOM) and not on every import route. The file name starts with EXTF_ and ends in .csv. The file is imported into DATEV through batch processing.

Example from everyday integration work

An ERP is supposed to hand all outgoing invoices to the tax firm at month-end. The integration generates an EXTF file with the header record for the right client and period and one line per invoice. The tax firm imports the file into DATEV Rechnungswesen. According to DATEV, the account length in the header record must match the client, otherwise the import fails or the accounts do not fit. The header record also defines whether the batch is locked on import (Festschreibung, posting lock). Locking is the default. That is why the header record is aligned with the tax firm before the first run.

How it differs from related terms

• DATEV posting batch (Buchungsstapel): the content, while the DATEV format is the form. A posting batch can be handed over as an EXTF file.
• DTVF: the same structure, but with the identifier for exports from DATEV programs.
• ASCII import: DATEV can also read freely structured text or CSV files, then with its own column assignment. The DATEV format, by contrast, is firmly defined.
• API: a route without a file. DATEV's online APIs have their own access rules.

Relevance to our services

For many companies the EXTF file is the fastest route into DATEV, because no approval from DATEV is needed for it, as long as the file goes to the tax firm. If you transfer it online through the Buchungsdatenservice (DATEV posting data service), DATEV has to check the file format. We generate it directly from your shop, ERP or CRM: DATEV integration. Which other routes exist is explained in the guide DATEV API.

Updated: 10/21/2026