DiamVAT

Check it, don’t guess it

DiamVAT queries your EU business partner’s USt-IdNr. through the official interface of the Bundeszentralamt für Steuern under section 18e no. 1 UStG (the German VAT Act) – simple or qualified. The answer arrives within seconds, in plain language, and carries the official time of the request rather than your device’s clock. German numbers are not answered by the BZSt at all. Those go through VIES at the European Commission and are visibly labelled as a VIES confirmation that is not official.

• Qualified confirmation: company name and address are assessed field by field – matches, differs, was not asked for, or was not supplied by the member state.
• That field-level comparison is the usual evidence of commercial diligence for the good-faith protection under section 6a(4) UStG. DiamVAT does not merely display it; it writes the whole of it into the PDF record.
• An attempt that was cancelled or failed for technical reasons never ends up in the record as “invalid”. Every failure gets its own status code (offline, cancelled, network or server error).
• Paste a number from text or read it off a photo of an invoice. Text recognition runs entirely on the device, and the image is never stored.

The record that counts with the tax office

Every check produces a PDF record containing everything an auditor wants to see: your own and the checked USt-IdNr., the official time of the check, the type of check, the result, the technical status code and the request ID. Batch runs get a multi-page report. It includes a separate section for every row that was never queried at all, with the reason spelled out. That way the arithmetic adds up: imported = documented + not checked.

• The check archive can be filtered by status and searched by number, company name and reference; one tap opens the stored individual record.
• Export as a multi-page PDF report and as CSV for reconciliation with your bookkeeping.
• The app never deletes anything of its own accord and has no automatic clear-out of old checks (sections 147 AO and 14b UStG). Deleting stays expressly your decision.
• The check records are archivable. Audit-proof in the strict sense are only the submission records, which survive even a “delete all local data”.

Hundreds in one go

Hand over the export from your bookkeeping as a CSV, text or Excel file. DiamVAT recognises the columns and proposes the mapping – nothing is imported automatically; you confirm the preview. The check then works through the rows one by one, deliberately one request at a time rather than in parallel, because parallel requests over a mobile connection returned false “invalid” answers in field testing.

• Every “invalid” is automatically checked a second time before it is allowed to stand in the record.
• Progress is visible, and each row carries its own result.
• Rows that were not queried do not simply disappear: they appear in the report with the reason why.

With the country rules of section 18a UStG built in

Enter reporting lines or take them from an import – DiamVAT knows the rules. German numbers do not belong in the Zusammenfassende Meldung, nor do non-EU numbers, and Northern Ireland (XI) counts for goods only. Lines that do not qualify are never deleted. They are visibly marked as “do not report” and can be brought back at any time. At the end you get a CSV in the ELSTER import format.

• The year grid shows the quarters with their three months alongside and the calendar year below; the rare two-month supplementary periods can be shown when you need them – 21 official reporting periods in all.
• What you may already file is tappable; what is still running carries a clock; what has not yet begun carries a padlock and, when tapped, the reason.
• The deadline – the 25th day after the period ends – sits right beside it, together with the reminder that a Dauerfristverlängerung does not apply to the Zusammenfassende Meldung.
• First and amended returns, monthly reporting under section 18a(1) sentence 2 with its coupling check, and the €50,000 threshold are all covered.

On the official form USt 1 A

The advance return follows the official form, with all 50 codes across eleven sections – each with its official number and an explanation. DiamVAT does the tax itself: the tax amount appears immediately below each taxable amount, the remaining prepayment always stays at the top, and the full calculation can be opened. Whenever you like, you can view the completed return as a three-page PDF of the official form.

• Checking starts as you type. Does the tax match the rate? Is the taxable amount missing for a tax figure? Is an amount negative where the authorities require none?
• For intra-community acquisitions and reverse-charge services under section 13b, the app proposes the corresponding input tax – as a suggestion you can overwrite; after that the automation never touches your entry again.
• Each tax year gets what is officially provided for it – code 23 up to 2025, for instance, and code 500 from 2026.

To ELSTER on the Mac – in test mode

The Mac app integrates the tax administration’s official ERiC interface (version 44.2.4.0). Its built-in check raises objections to your return in exactly the words the acceptance server would later use, without any network contact at all. Important, and said plainly: in this version transmission goes solely to the tax administration’s test system – filing with legal effect is deliberately not possible. All four types of return have in fact been transmitted this way to the test system and accepted there.

• Before sending, the app reads back the string that will actually be transmitted and asks you to type a confirmation word.
• The ELSTER certificate (.pfx) is checked for authenticity and PIN as you store it, and the holder and validity are displayed. The PIN stays on that device behind Face ID or Touch ID; the certificate file itself deliberately travels through the iCloud keychain.
• Every accepted submission files a record: date of sending, recipient, period, certificate, manufacturer ID, transfer ticket, the figures from the XML that was sent, and the server’s reply – as a PDF. It survives deleting the draft just as it survives “delete all local data”.
• The tax administration’s legal notes – the document on Articles 12 to 14 GDPR, the data protection notice verbatim, the note that log files stay on your device, and the recommendation to keep backups – are shown and acknowledged before first use, with the date and document version, and remain available at any time.
• For the Wirtschafts-Identifikationsnummer (the German business identification number), the app automatically strips off the five-digit distinguishing feature, because the official fields accept only DE plus nine digits.

Several companies, one overview

Create as many companies as you need, each with its own USt-IdNr., tax number, legal form, short name and notes. The active company determines what the app shows: check history, imports, EC Sales List rows, advance returns and annual returns always belong to it. You switch at the top of the dashboard or in the sidebar.

• The dashboard is the first thing you see: seven figure tiles, quick actions, open notes, the most recent checks and imports, and the state of the Zusammenfassende Meldung. “Officially checked” deliberately excludes the VIES answers.
• The tiles are built from count queries, so the view opens just as quickly with 5,000 records in the archive as with 500.
• You type the tax number exactly as it appears on your assessment; DiamVAT converts it into the 13-digit ELSTER format – confirmed for all 16 federal states. The app also names the tax office, drawing on the official directory of 746 offices.
• The same USt-IdNr. on two companies is reported as an error and blocks submission: two companies cannot file under one VAT number.