Accounting guides, by market
Every market has its own statutory handoff and its own file format. These explain what each one actually requires, written from the code that produces it.
DATEV export explained: the EXTF Buchungsstapel, field by field
What a DATEV EXTF Buchungsstapel actually requires: CP1252 encoding, decimal comma, Soll/Haben flags, TTMM Belegdatum, and how to decompose a multi-line journal entry into Konto and Gegenkonto without inventing an account.
FranceFEC export explained: the eighteen columns the DGFiP requires
What a Fichier des Écritures Comptables actually requires: eighteen mandatory columns in a fixed order, tab separated, decimal comma, dates as YYYYMMDD, one row per journal line, and the {SIREN}FEC{clôture}.txt naming convention.
EuropeEN 16931 e-invoicing explained: what the file must contain
What a PEPPOL BIS Billing 3.0 e-invoice actually requires under EN 16931: the VAT category codes, when an exemption reason is legally mandatory, the buyer reference, and why the document itself can be produced offline without paying anyone.
United StatesUS sales tax for ERP: nexus, destination sourcing and rooftop rates
Why US sales tax cannot be modelled as a VAT: the nexus gate that decides whether you collect at all, destination-based sourcing that sets the rate from the ship-to address, the five states with no state-level tax, and what a state base rate does not include.