UStVA + Claude

German VAT return with Claude: the UStVA from your figures to your PIN

You can prepare the German VAT return with Claude: Claude reads the advance VAT return (Umsatzsteuer-Voranmeldung, UStVA) figures from your books, asks you the form's special-case questions, runs the official ELSTER check without sending anything and prepares the filing — then you file it yourself in the app with your ELSTER PIN, through an approval link Claude gives you. Reading the figures needs read access only; the check and the preparation need the Post right.

Last reviewed: 2026-10-30

The UStVA in brief

A business that charges German VAT files advance returns electronically, by the 10th day after the end of each period (§ 18(1) UStG). The period is normally the calendar quarter. It becomes the month if last year's VAT exceeded € 9,000, and the tax office can waive advance returns if it was no more than € 2,000 (§ 18(2) UStG). For newly founded businesses, a transitional rule for 2021 to 2026 bases the period on the annualised or expected tax instead of requiring monthly returns from the start.

The permanent extension (Dauerfristverlängerung) moves every deadline by one month (§ 46 UStDV). Monthly filers then pay a special prepayment of one eleventh of last year's prepayments (§ 47 UStDV), and the application is due by the date on which the first return it covers would be due (§ 48 UStDV).

The conversation, step by step

A quarterly filer, third quarter of 2026, connected with read access and the Post right:

You:     Get the Q3 VAT return ready. Ask me whatever the form needs.

Claude → get_vat_return              period 2026-Q3   boxes, amount payable
       → get_vat_supplementary       period 2026-Q3   the form's questions
Claude:  The form asks about special cases — triangular deals,
         VAT shown on an invoice without being owed, input-VAT
         adjustments and others. Does any of them apply?
You:     None of them.
Claude → confirm_vat_supplementary   only after your “none”
       → check_tax_filing            official ELSTER check, nothing sent
       → prepare_tax_filing          figures frozen for 30 minutes
       → request_tax_filing_approval link valid for 7 days
Claude:  The check passed. Here is your approval link.

You open the link in the app, compare the prepared figures with
a fresh calculation, and file with your ELSTER PIN.

Example figures

An example quarter for a company that invoices German customers at 19 % and pays for an EU software subscription; every amount is an example:

Box 81, taxable sales at 19 %: € 24,000 net, € 4,560 VAT.
Box 66, input VAT from German suppliers' invoices: € 1,710.
Boxes 46 and 47, EU service under reverse charge (§ 13b UStG): € 360 net and € 68.40 VAT that you owe as the recipient.
Box 67, the same € 68.40 deducted as input VAT — with full deduction the reverse charge nets to zero, but both boxes are filled.
Box 83, advance payment: € 4,560 + € 68.40 − € 1,710 − € 68.40 = € 2,850.

get_vat_return shows each box together with the postings behind it, so Claude can tell you which invoice drives a figure. Tax bases are cut to whole euros, as in the official calculation, which can explain a difference of a few cents against the VAT accounts.

The form's special-case questions

The official form contains questions that only matter in special cases. get_vat_supplementary returns them with their official wording for the period. Claude may confirm one answer on your behalf — that none of them applies — and only after you have said so. If one does apply, you record it in the app; recorded answers are never overwritten through Claude. Until the questions are settled, the check and the preparation report an open obstacle instead of passing.

Check, prepare, approve: four different steps

check_tax_filing

The official ELSTER validation (ERiC) with the test flag. It shows whether the return would be accepted and lists field errors; nothing is transmitted, not even from the sandbox.

prepare_tax_filing

Freezes the box figures and a fingerprint (manifest_sha256) for 30 minutes and lists every obstacle. Still nothing is sent.

request_tax_filing_approval

Creates a link valid for 7 days. In the app, signed in, you see the prepared figures next to a fresh calculation; if a posting changed in the meantime, you see it before filing.

get_tax_operation

Afterwards Claude reads the status, including the transfer ticket once you have filed.

Deadlines, the permanent extension and the EC sales list

list_tax_deadlines gives Claude the same deadlines as the tax calendar in the app — advance returns, special prepayment, EC sales lists, annual returns — each with its due date and whether it is done or overdue. Ask “What is due in November?” and Claude answers from that list, not from general knowledge.

For the permanent extension, create_tax_draft with art dauerfrist builds the current year's application from the books. It covers the regular case only: Claude first asks you to confirm that there is nothing to add, that no direct-debit mandate is being revoked and that last year's prepayments are the official reference. The draft then goes through check, preparation and approval like a VAT return. The EC sales list (Zusammenfassende Meldung, § 18a UStG) for supplies and services to business customers in other EU countries works the same way, with art zm and a period.

Limits

Claude never transmits to ELSTER; a right for that is not granted. You file in the app with your PIN, and the PIN never goes into the chat.
Corrected returns are filed in the app, not through Claude.
Special cases in the form's questions, the VAT period, cash or accrual taxation and the extension setting are changed in the app.
Per company one filing at a time; per key at most 30 checks and preparations an hour.
What a filing costs depends on your subscription; see the prices page.
Claude's figures and explanations are proposals; you remain responsible for the return you file.

Which Claude, which right

Any of the Claude routes works: the connector in claude.ai or the Claude mobile app (tick “Post” on the consent page), the desktop extension, or Claude Code with a key that has the Post right. With read access only, Claude can show you the figures and the deadlines but cannot run the check or prepare the filing.

A company that uses only the tax module, without the bookkeeping, can connect too: its key or connection reaches the tax tools and the company's master data.

Frequently asked questions

Can Claude submit my German VAT return?

No. Claude checks and prepares it and gives you an approval link; you file in the app with your ELSTER PIN.

When is the UStVA due?

By the 10th day after the end of the month or quarter (§ 18(1) UStG); with the permanent extension one month later (§ 46 UStDV).

Does Claude ever see my ELSTER PIN?

No. You enter it only in the app, when you file through the approval link.

What if a posting changes after Claude prepared the return?

When you open the link, the app recalculates and shows changed figures before anything is sent. You can also ask Claude to prepare the return again.

Can Claude correct a VAT return I already filed?

No. Corrected returns are made in the app.

Can Claude apply for the Dauerfristverlängerung?

In the regular case, yes: it creates the current year's application from your books, checks and prepares it, and you file it through the approval link.