Germany USt pack (`khata-de`)¶

KhataOS can keep books for a German business: it checks the USt-IdNr and the Steuernummer, charges 19%, 7% or 0% USt on invoices (with the 16% / 5% of the second half of 2020), handles the §13b reverse charge, checks invoice numbers, works out the UStVA (Umsatzsteuer-Voranmeldung) from the books, and writes XRechnung 3.0 invoices (UBL or CII) through the shared EN 16931 crate (docs/en16931.md). Nothing is sent to ELSTER or to a buyer. Nothing here is tax advice: check the figures with your Steuerberater before you file.

Code: crates/khata-de (the rules: ustid.rs, steuernummer.rs, laender.rs, ust.rs, returns.rs, xrechnung.rs, leitweg.rs), apps/desktop/src-tauri/src/vat_de.rs (vouchers to UStVA documents and XRechnung invoices; the ustva(from, to) and xrechnung_xml(voucher_id, syntax) commands) and apps/desktop/src/screens/vat_de.ts (UstvaReport, exportXRechnung); see Where it is in the app. Sources and open questions are in docs/research/germany-compliance.md. Tags: [PRIMARY] read in the law, a BMF letter, ELSTER or KoSIT material; [SECONDARY] reported by other sources; [UNCERTAIN] not confirmed.

Setting up a German company¶

Pick Germany as the country. The books use EUR (2 decimals, "€") and calendar years: the Wirtschaftsjahr is the calendar year unless a business in the Handelsregister chooses another (§4a Abs. 1 EStG).
In Company → Company details (Alt+K), enter the USt-IdNr (or the Steuernummer, when the company has no USt-IdNr) and pick the Bundesland (ISO 3166-2:DE without "DE-": BW, BY, BE, BB, HB, HH, HE, MV, NI, NW, RP, SL, SN, ST, SH, TH). The Land never changes the rate. A 13-digit Steuernummer gives its own Land.
Add the rate list (also in khata_de::ust::default_rates):

Class	Rate	From	Notes
`STANDARD`	19%	1 Jan 2007	16% from 1 Jul to 31 Dec 2020 (§28 Abs. 1 UStG) [PRIMARY]
`REDUCED`	7%	1 Jan 2007	5% from 1 Jul to 31 Dec 2020 (§28 Abs. 2) [PRIMARY]; restaurant food is 7% from 1 Jan 2026 (§12 Abs. 2 Nr. 15) [PRIMARY]
`ZERO`	0%		taxable at 0% (§12 Abs. 3, photovoltaics)
`EXEMPT`	0%		tax-free under §4 (Nr. 8 ff.)
`REVERSE`	0%		§13b: the recipient owes the tax

Names matter: a class starting with EXEMPT is tax-free, REVERSE is reverse-charged, REDUCED is reduced; any other 0% class is zero-rated. 4. Put the contact and bank details on extra lines of the company address (until the profile has fields for them); XRechnung needs them:

Hauptstraße 1
10115 Berlin
Tel.: +49 30 123456
E-Mail: rechnung@muster.de
Kontakt: Erika Muster
IBAN: DE02 1203 0000 0000 2020 51
BIC: BYLADEM1001

Tax identifiers¶

USt-IdNr: DE and nine digits; the ninth is an ISO 7064 MOD 11,10 check digit over the first eight [SECONDARY: Wikipedia de, python-stdnum; ELSTER publishes the same algorithm for the Steuer-IdNr, PRIMARY]. The prefix may be left out. A number starting with 0 is refused, as python-stdnum does [UNCERTAIN: no official text]. A pass shows the number is well formed; only the BZSt (eVatR) or VIES say it is valid.
Steuernummer: the printed form (10 or 11 digits with the state's grouping) or ELSTER's 13-digit form FFFF0BBBUUUUP (NRW FFFF0BBBBUUUP). The 13-digit form is checked fully: state prefix, the 0 in position 5, the Bezirk rules and the state's check digit (11er, NRW, modified 11er for Rheinland-Pfalz, 2er for BW/HE/SH), from ELSTER's Prüfung der Steuer- und Steueridentifikationsnummer (Stand 02.09.2026) [PRIMARY]. Berlin's choice of method A or B per Finanzamt is not implemented: either is accepted. A printed number is accepted when it fits some state's form and check digit (the Land is given only when exactly one state fits); steuernummer::to_elster(id, land) converts.
Other EU VAT identifiers (for EU customers and suppliers) are accepted on their shape only: an EU prefix (EL for Greece) and 2 to 12 letters or digits.
Leitweg-ID (the Buyer reference of a public buyer): leitweg::validate checks the shape and the MOD 97-10 check number (Format-Spezifikation 2.0.2) [PRIMARY].

Invoices¶

Invoice and credit-note numbers must be given once (§14 Abs. 4 Nr. 4: "eine fortlaufende Nummer … die … einmalig vergeben wird") [PRIMARY]: KhataOS refuses a number used before in the series in any year (case-insensitive). At most 35 characters of letters, digits, - and /: a KhataOS choice, not law.
USt is one "USt" component per line, rounded to the cent, half away from zero (no rounding rule in the UStG [UNCERTAIN]). A REVERSE line is 0% whatever its rate on file; a supply abroad is 0%.
Duty ledgers for USt use the tax type USt (VAT is also read).

UStVA¶

ustva(from, to) works out the Kennzahlen of form USt 1 A (2025 and 2026 forms, BMF letters of 9 Dec 2024 and 29 Dec 2025) [PRIMARY] for a month or a quarter. Bases are whole euros, taxes euros and cents, as the form asks [PRIMARY]; cents are dropped (toward zero) rather than rounded [UNCERTAIN: the form does not say]. The tax on Kz 81 and 86 is base × rate, as the form computes it; a warning appears when the USt booked differs by more than €1.

Kz	What	From
81 / 86	taxable at 19% / 7% (base; tax computed)	Sales and Credit Notes
35 / 36	other rates (16% / 5% of 2H 2020, corrections): base and tax booked
87	taxable at 0% (§12 Abs. 3)	`ZERO` class
41	tax-free intra-EU supplies of goods to buyers with a VAT id	goods to an EU party with a VAT id, no USt
43	other tax-free supplies with input-tax deduction (exports)	goods to a party outside the EU, no USt
48	tax-free without input-tax deduction	`EXEMPT` class
60	supplies where the recipient owes the tax (§13b)	`REVERSE` class
21	services taxable in another EU state (§18b)	services to an EU party with a VAT id, no USt
45	other supplies not taxable in Germany	services to a party outside the EU
89 / 93	intra-EU acquisitions at 19% / 7% (tax computed)	goods from an EU supplier, no USt
46 / 47	services from EU businesses (§13b Abs. 1)	services from an EU supplier, no USt
84 / 85	other §13b supplies received	`REVERSE` purchases, services from outside the EU
66	input tax from invoices	USt booked on Purchases and Debit Notes
61 / 67	input tax on acquisitions / on §13b	the self-assessed tax, deducted again
83	remaining prepayment (positive) or refund (negative)	output tax − input tax

Where a party is comes from its ledger's mailing country (empty or DE: Germany). A sale or purchase with USt booked is always domestic. Reverse-charge and acquisition tax is self-assessed at the class's rate, or the STANDARD rate when the class is 0%.

Not worked out: Kz 42 (triangular trade), 44/49 (new vehicles), 73/74, 76/80, 95/98, 94/96, 90/91, 62 (import VAT: goods bought from outside the EU get a warning), 59, 63, 64, 65, 69, 39 (Sondervorauszahlung), 37, 10, 22, 26, 29, 70 and 500; Istversteuerung; partial input-tax deduction; §15a; the Zusammenfassende Meldung; the annual return.

Filing [PRIMARY, §18 UStG]: quarterly by default; monthly when the previous year's tax was more than €9,000; exemption possible up to €2,000; due on the 10th day after the period (one month later with Dauerfristverlängerung). Only electronically through ELSTER: third-party software uses ERiC, a free C library that needs a Hersteller-ID. KhataOS does not submit (see Next steps).

XRechnung¶

xrechnung_xml(voucher_id, syntax) maps a saved Sales (380) or Credit Note (381) voucher to the EN 16931 model (khata_de::xrechnung::to_en16931) and writes it as UBL 2.1 ("ubl") or UN/CEFACT CII D16B ("cii") with the XRechnung 3.0 CustomizationID urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0 [PRIMARY: KoSIT Schematron v2.6.0]. The answer carries the XML, a file name, errors (broken EN 16931 or BR-DE rules: not a valid XRechnung until fixed) and warnings. Save it with write_gst_json (it accepts .xml).

Seller: the company name, its USt-IdNr (BT-31) or Steuernummer (BT-32), and the address block above (BT-35 ff., contact BG-6, e-mail as electronic address BT-34, IBAN/BIC as SEPA credit transfer 58). Without an IBAN the payment means is "1" (not defined), with a warning.
Buyer: the party ledger's name, VAT id (a Steuernummer is not put in BT-48), mailing address and post code, country, and e-mail (BT-49).
Buyer reference (BT-10, required by BR-DE-15): a line Leitweg-ID: … (or Buyer reference:, Käuferreferenz:, Ihre Referenz:) in the voucher narration; the other narration lines become invoice notes (BT-22). A reference shaped like a Leitweg-ID with a wrong check number gets a warning. (BMF 15 Oct 2025: a missing BT-10 is "umsatzsteuerlich unbeachtlich" [PRIMARY], but the XRechnung rule still fails.)
Dates: the supply date (BT-72) is the invoice date (the books have no separate Leistungsdatum yet; a warning says so); the due date (BT-9) from the party's bill or credit days.
Categories and notes (§14 Abs. 4 Nr. 8, §14a): 19%/7% → S; ZERO → Z; EXEMPT → E with "Steuerfreie Leistung nach § 4 UStG" (a warning asks to name the provision); REVERSE → AE with "Steuerschuldnerschaft des Leistungsempfängers" (the wording of §14a Abs. 5) [PRIMARY]; intra-EU goods → K ("Steuerfreie innergemeinschaftliche Lieferung", VATEX-EU-IC, deliver-to country = buyer's); exports → G (VATEX-EU-G); services to an EU business → AE (§14a Abs. 1); other supplies abroad → O. Each note is also an invoice note. A Kleinunternehmer (§19) invoice would be E with the §19 note (Seller::kleinunternehmer), but the profile has no such flag yet. Kleinunternehmer invoices are exempt from the e-invoice obligation (§34a UStDV) [PRIMARY].
Units: stock units map to UN/ECE Rec 20 codes (Stk/Nos → H87, kg → KGM, Std → HUR…); others become C62 with a warning.
Discounts (ledgers on the party's side) become document allowances in the first line's category.

The e-invoice obligation (Wachstumschancengesetz, §14 and §27 Abs. 38 UStG; BMF letters of 15 Oct 2024 and 15 Oct 2025) [PRIMARY]: every business must be able to receive e-invoices from 1 Jan 2025; for domestic B2B supplies, paper or other electronic invoices remain allowed in 2025 and 2026, in 2027 only for issuers with prior-year turnover up to €800,000 (and EDI with consent), and from 2028 every domestic B2B invoice must be an e-invoice (EN 16931: XRechnung, or ZUGFeRD from 2.0.1 except MINIMUM and BASIC-WL). Exceptions: invoices up to €250 (§33 UStDV), tickets, Kleinunternehmer, §4 Nr. 8–29 supplies, B2C. Retention: invoices 8 years (§14b UStG), books 10 years (§147 AO, after the Bürokratieentlastungsgesetz IV); keep the XML as received (GoBD as amended 14 Jul 2025) [PRIMARY]. KhataOS keeps the books; it does not archive received XML files yet.

ZUGFeRD / Factur-X¶

A ZUGFeRD invoice is a PDF/A-3 with the CII XML embedded (factur-x.xml, or xrechnung.xml for the XRECHNUNG profile), AFRelationship "Alternative", and XMP metadata in the fx namespace (urn:factur-x:pdfa:CrossIndustryDocument:invoice:1p0#: DocumentType, DocumentFileName, Version, ConformanceLevel) [SECONDARY: Mustang]. The current version is ZUGFeRD 2.5.2 / Factur-X 1.09.2 (Aug 2026) [PRIMARY: ferd-net.de]. khata_en16931::cii::write already produces the XML for the EN 16931 (urn:cen.eu:en16931:2017) and XRECHNUNG profiles. khata_en16931::facturx wraps the EN 16931 XML in a PDF/A-3b container with the fx XMP metadata, and peppol.rs facturx_pdf builds it from a voucher: Ctrl+E (Export) on a saved Sales invoice or Credit Note → Factur-X / ZUGFeRD PDF. Still open: only the EN 16931 profile is written (not XRECHNUNG inside the PDF), the visible page is plain text rather than the invoice design, and the file has not been run through a PDF/A validator.

Where it is in the app¶

UStVA: Go To (Alt+G) → UStVA (Germany VAT return), shown only for German companies. F2 changes the period; Ctrl+P prints and Ctrl+E saves a CSV.
XRechnung: on a saved Sales invoice or Credit Note, Ctrl+E (Export) → XRechnung (UBL or CII), which asks for the syntax and saves the XML.
Factur-X: the same menu → Factur-X / ZUGFeRD PDF (above).

Next steps¶

Company profile fields for contact, e-mail, IBAN/BIC, Handelsregister number (BT-30, needed by BR-CO-26 when the company has only a Steuernummer) and the Kleinunternehmer flag; a Leistungsdatum per voucher; a buyer-reference field per party (Leitweg-ID).
ELSTER submission through ERiC (licence and redistribution for an open-source app are open questions in the research).
Zusammenfassende Meldung (Kz 41 and 21 by buyer VAT id).
The XRECHNUNG profile inside ZUGFeRD, and the invoice design on its page; receiving and archiving e-invoices (XML import, GoBD).
Run the KoSIT validator on generated samples in CI.

Germany USt pack (khata-de)¶