SEPA Direct Debit & DATEV Export Knowledge Modules

The accounting-export half of German billing QA: the EXTF/Buchungsstapel CSV that third-party systems hand to a tax adviser's DATEV, its header and record format, the traps that import cleanly and book wrongly, and the SKR chart-of-accounts landscape — including the non-profit tax spheres whose loss is this module's highest-value test. The payment-rails half is sepa-direct-debit; the shared failure taxonomy, fixture matrix and validation heuristics live in this pack's root. Verified against the official DATEV sample file EXTF_Buchungsstapel.csv from DATEV's public Muster bundle (file dated 2025-06-18). Structure: Line 1 — the header, 31 fieldsLine 2 — column names, 125 columnsLine 3 onward — booking records Header fields, by position (values shown are the sample's): File-level rules that cause silent non-import (DATEV help document 1044208): the filename must begin EXTF_ and end .csv; a Buchungsstapel holds at most 99,999 rows (a 5-digit record counter) — once Saldo- and Gruppensummenzeilen are counted the usable posting count is 99,997, so the boundary trips before 100,000; the client's Berater/Mandant/fiscal-year must match the target ledger; and if line 1 is missing, DATEV simply does not offer the file for import. DATEV's own diagnostic is to open the file and check that cell A1 reads EXTF — if it reads Umsatz (ohne Soll/Haben-Kz), the header line was dropped. Record field order — the first 14 columns, which carry the booking: A third-party export that names columns like Umsatz, S/H, BU, Gegenkonto, Belegfeld, Konto, KOST1, Buchungstext is a Buchungsstapel-shaped file even when the vendor never uses the word — hold it to this format.

The format layer of SEPA direct-debit QA: the pain.008 message and its character rules, the mandate lifecycle and sequence types, collection timing, CORE vs B2B, R-transaction reason codes, and IBAN/Creditor-Identifier validation. It exists so a QA report can say which field is wrong and which rule it violates — with the EPC index number — rather than "the button did not error". The operational layer — failure taxonomy, synthetic fixture matrix, and the run-them-all validation heuristics — lives in this pack's root; the accounting-export half is datev-extf. Version pinning matters here: a rule from the wrong scheme or the wrong year gives money-path QA false confidence, which is worse than no module. Version pinning matters here: a rule from the wrong scheme or the wrong year gives money-path QA false confidence, which is worse than no module. All retrieved and text-extracted 2026-08-08. Message version: pain.008.001.08. The Core IG states it implements the 2019 ISO 20022 message version; the B2B IG maps the same Customer Direct Debit Initiation V08. A club still emitting pain.008.001.02 is on the pre-2023-migration version — flag it, do not assume the bank still accepts it. EPC135-18 "Guidance on Reason Codes" covers SCT (credit transfers), not direct debits. It is easy to find and easy to cite by mistake. Use the SDD IG for direct-debit reason codes. Three nested levels. Getting the level right is most of the job — a field checked at the wrong level is the most common false bug report.