Terms of use
These terms apply to the DiamVAT app. The same version is available in the app under Settings → Legal. In case of doubt, the German version prevails.
1. Provider and scope
DiamVAT is provided by DiamApps; address and contact details are in the legal notice at diamapps.com/impressum. These terms apply to the use of the app on iPhone, iPad and Mac. For purchases through the App Store, Apple’s terms also apply, in particular the standard licence agreement for apps.
2. What DiamVAT does
DiamVAT validates VAT ID numbers via the official interfaces of the German Federal Central Tax Office and the European Commission (VIES), documents the results and prepares the EC sales list, the advance VAT return, the filing extension, the annual VAT return and messages to the tax office following the official forms. On your instruction DiamVAT submits these reports to the tax administration with your own ELSTER certificate. DiamVAT is a tool: it does not provide assistance in tax matters within the meaning of the German Tax Advisers Act and does not replace tax advice.
3. Your responsibility
You are responsible for the accuracy and completeness of your entries, the choice of report type and period, meeting the deadlines and keeping your records. Check every report before submitting it. Only submit for companies for which you are authorised to do so, and only with a certificate that belongs to you or that you are entitled to use. Keep the certificate file and the PIN safe.
4. Official interfaces and submission service
The availability of the BZSt, VIES and ELSTER interfaces is beyond our control. On iPhone and iPad, DiamVAT uses its own submission service for the official check and the submission; we strive for high availability but cannot guarantee it. Allow for a margin before deadlines; filing via “My ELSTER” remains possible at any time. The tax administration’s transfer ticket is decisive for a filing.
5. Purchases and trial
DiamVAT Basic is free. DiamVAT Pro is a one-time purchase through the App Store; the 14-day trial is free, ends automatically and is not charged. Payment and refunds are governed by Apple’s terms.
6. Liability
We are liable without limitation for intent and gross negligence, for injury to life, body or health and under the German Product Liability Act. In the case of slight negligence we are only liable for breaches of essential contractual obligations whose fulfilment makes the proper use of the app possible in the first place and on whose observance you may rely, and only up to the foreseeable damage typical for this kind of contract. Beyond that we are not liable for damage resulting from incorrect or incomplete entries, missed deadlines or the unavailability of official interfaces.
7. Data protection
How DiamVAT handles data is described in the privacy notes in the app (Settings → Privacy) and in the privacy policy at diamapps.com/en/privacy.
8. Changes and applicable law
We may amend these terms with effect for the future; the current version is available in the app and on the website. German law applies; mandatory consumer protection provisions of the country in which you have your habitual residence remain unaffected.
Version: 13 October 2026