E‑invoicing that keeps up with your work.

1. Controller

Zentrix Lab OÜ, Telliskivi tn 57, 10412 Tallinn, Estonia, represented by Nenad Gligorić. Contact: hello@zen-rechnung.de.

2. Overview

This policy explains what personal data we process when you visit this website and when you use the Zen Rechnung app, for what purposes, on what legal basis, and what rights you have. We only process personal data where this is necessary and permitted by applicable data protection law, in particular the GDPR.

3. Legal bases we rely on

Depending on the processing activity, we rely on: your consent (Art. 6(1)(a) GDPR); the performance of a contract with you or steps taken at your request before entering into one (Art. 6(1)(b) GDPR); compliance with a legal obligation, such as German tax retention rules (Art. 6(1)(c) GDPR); or our legitimate interest in operating a secure, functioning service (Art. 6(1)(f) GDPR). The relevant basis is named for each processing activity below.

4. Visiting this website

This marketing website does not use cookies, analytics or tracking scripts. Fonts are hosted locally rather than loaded from a third party, so visiting this site does not send any data to an external font provider.

When you select a language, that choice is stored locally in your browser (not a cookie) so the site remembers it on your next visit. This is technically necessary for that function and is not used for any other purpose (legitimate interest, Art. 6(1)(f) GDPR).

Your hosting provider automatically records standard server log data (such as IP address, date and time of access, browser type and referring page) for security and stability purposes, as is standard for any web server. This data is used only to keep the website secure and is not combined with other data about you (legitimate interest, Art. 6(1)(f) GDPR).

5. Contact form

When you use the contact form, your browser opens your own email application with a pre‑filled message addressed to hello@zen-rechnung.de. The data you enter (name, email, company, message) is sent directly from your device to our inbox by email, at your initiative (Art. 6(1)(b) GDPR, pre‑contractual inquiry). This website itself does not store, process or transmit that data through any server of ours.

6. Creating an account and using the app

When you create an account and use the Zen Rechnung app, we process the account and company data you provide — such as your name, email address, company details and bank details — in order to provide the service and fulfil our contract with you (Art. 6(1)(b) GDPR).

7. Invoice, customer and partner data you enter

When you enter your own customers', suppliers' or partners' data into the app to create invoices and other documents, that data remains your responsibility: you are the controller for that data, and we process it only as your processor, on your instructions, as is standard for invoicing and accounting software (Art. 28 GDPR). A data processing agreement (Auftragsverarbeitungsvertrag) is available on request.

8. Payment processing

Paid plans are billed through Stripe, our payment service provider, from the moment you select them. Stripe processes the payment data required to complete your payment (such as card details) directly; we do not store your full card details ourselves. This is necessary to perform our contract with you (Art. 6(1)(b) GDPR). Stripe may process this data outside the EU/EEA, based on the EU Commission's Standard Contractual Clauses or another valid transfer mechanism offered under its standard terms.

9. Transactional emails

We use SendGrid (Twilio) to send account, invoice and notification emails that are part of the service (Art. 6(1)(b) GDPR). This may involve processing your email address and the relevant email content outside the EU/EEA, based on the EU Commission's Standard Contractual Clauses or another valid transfer mechanism offered under SendGrid's standard terms.

10. Sharing invoices via WhatsApp

If you actively choose to share an invoice with your customer via WhatsApp, a link to download the invoice PDF is sent through WhatsApp (operated by Meta) to your customer's WhatsApp number, at your instruction (Art. 6(1)(b) GDPR). The data involved (the link and the recipient's number) is processed by Meta as part of sending that message, which may involve a transfer outside the EU/EEA. This only happens when you use this optional feature.

11. Affiliate referral attribution

If you arrive at the app through a link from one of our affiliate partners, a referral code contained in that link is automatically saved in your browser's local storage for up to 30 days, so that if you register within that period — even later, not immediately — the signup can be attributed to that partner. You do not need to enter anything yourself. This storage is first‑party only (used solely for partner attribution, never for advertising or cross‑site tracking) and is based on our legitimate interest in operating our affiliate program (Art. 6(1)(f) GDPR). No cookie is set for this purpose.

12. Hosting

The app is hosted with DigitalOcean, in a German (Frankfurt) data center.

13. Recipients of your data

Depending on which features you use, your data may be processed by: Stripe (payment processing), SendGrid/Twilio (transactional email), Meta/WhatsApp (only if you use the WhatsApp sharing feature), and DigitalOcean (hosting). We do not sell personal data to third parties, and we do not use it for advertising.

14. International data transfers

Where any of the providers listed above process data outside the EU/EEA, this is based on the EU Commission's Standard Contractual Clauses or another valid transfer mechanism included in that provider's standard terms.

15. Retention

Invoices and related accounting documents must be retained for 8 years under German tax law (§ 147 AO). Other account data is kept for as long as your account is active, plus any period required by law afterwards. Data you submit through the contact form is not stored by us at all, as explained above.

16. Data security

We use industry‑standard transport encryption (TLS/HTTPS) to protect data in transit, and access to account and company data is restricted to what is necessary to provide the service.

17. Automated decision-making

We do not use automated decision-making or profiling that produces legal effects concerning you or similarly significantly affects you.

18. Your rights

Under the GDPR, you have the right to: request access to the personal data we hold about you (Art. 15); request correction of inaccurate data (Art. 16); request deletion of your data where applicable (Art. 17); request restriction of processing (Art. 18); receive your data in a portable format (Art. 20); object to processing based on our legitimate interest (Art. 21); and withdraw any consent you have given, at any time, without affecting the lawfulness of processing before the withdrawal (Art. 7(3)). You can exercise these rights by writing to hello@zen-rechnung.de.

19. Right to complain

You also have the right to lodge a complaint with a data protection supervisory authority, in particular in the EU/EEA country of your habitual residence, place of work, or the place of the alleged infringement.

20. Providing your data

Providing the data needed to create an account and issue invoices is necessary to use the service; without it, we cannot provide the service to you. Providing other data (such as in the contact form) is voluntary.

21. Changes to this policy

We may update this policy as the website or the service changes. The current version, as published here, always applies.

1. Scope

These terms apply to the use of the Zen Rechnung e-invoicing service ("Service"), provided by Zentrix Lab OÜ, Telliskivi tn 57, 10412 Tallinn, Estonia ("we", "us", "Zentrix Lab"), accessible at deinvoice.zentrix.io. This website is for information purposes; the service agreement is formed when you create an account in the app and accept these terms.

2. Who can use the service

The Service is intended for businesses, freelancers, accountants and similar professional users issuing invoices in the course of their trade, business or profession, not for purely private, non‑commercial use.

3. Free plan and pricing

We offer a permanently free plan with limited features (current limits are shown in the app). Paid plans (Business, Group, Büroservice) are billed through Stripe, our payment service provider, from the moment you select them; prices and billing cycles are shown in the app before you choose a paid plan. You can cancel a paid plan at any time.

4. Your account

You are responsible for keeping your login credentials confidential and for all activity under your account. Notify us without delay if you suspect unauthorised use of your account.

5. Your responsibilities

You are responsible for the accuracy of the invoices and the company, customer and partner data you enter and issue through the Service, and for complying with the tax, accounting and invoicing obligations that apply to your business. You agree to use the Service only for lawful purposes and not to misuse it (for example, to send unlawful, fraudulent or infringing content).

6. No tax or legal advice

The Service helps you create invoices in formats designed to meet common German e‑invoicing requirements (such as XRechnung and ZUGFeRD), but it does not constitute tax, accounting or legal advice, and we do not review your individual tax situation. You remain responsible for ensuring that your invoices and your use of the Service comply with the law that applies to you, and we recommend consulting a tax advisor for matters specific to your business.

7. Availability and changes

We aim to keep the Service available and reliable, but we do not guarantee uninterrupted or error‑free availability, including during maintenance or due to circumstances outside our reasonable control. Features may be added, changed or removed as the product evolves; we will aim to give reasonable notice of changes that materially reduce the Service's functionality.

The limits of our free plan (such as the number of contacts, invoices or deliveries included) are not a paid contractual entitlement, and we may change them at any time without prior notice. For paid plans, we will give you at least 30 days' notice of any price increase or material reduction in included features before it takes effect; you may object to the change or cancel your plan within 14 days of that notice, and if you do not, the change becomes part of our agreement with you.

8. Your data and backups

You remain the owner of the data you enter into the Service. You are responsible for keeping your own copies or exports of important data where this matters to you. We are not liable for loss of data except where this is caused by our intent or gross negligence.

9. Intellectual property

The Service, including its software, design and trademarks, is owned by Zentrix Lab OÜ or its licensors and is protected by applicable intellectual property laws. These terms do not grant you any rights in our intellectual property beyond the right to use the Service as intended.

Features offered under the Custom plan — such as integrations with your own systems, bespoke development work, or other individually agreed requests — are not part of the standard Service and are provided, if at all, only under a separate written agreement setting out their scope, price, delivery and intellectual property terms. These Terms govern your use of the standard Service only; they do not by themselves grant you, or us, any rights in work delivered under such a separate agreement beyond what that agreement states.

10. Suspension and termination

You may stop using the Service and close your account at any time. We may suspend or terminate your access if you materially breach these terms, misuse the Service, or if required by law, and will give notice where reasonably possible. Provisions that by their nature should survive termination (such as liability and governing law) continue to apply.

11. Liability

To the extent permitted by law, our liability is limited to intent and gross negligence, and otherwise to foreseeable, contract‑typical damage, except where liability is mandatory under applicable law (for example for injury to life, body or health, or under mandatory product liability law). We are not liable for indirect or consequential damages, such as lost profits, except in cases of intent or gross negligence.

12. Indemnification

You agree to indemnify us against reasonable claims, damages and costs arising from your misuse of the Service, your breach of these terms, or the data and content you submit through the Service, except to the extent caused by our own intent or gross negligence.

13. Changes to these terms

We may update these terms from time to time, for example to reflect changes to the Service or legal requirements. Where changes materially affect your rights, we will give reasonable notice before they take effect.

14. Dispute resolution

The European Commission provides a platform for online dispute resolution, available at ec.europa.eu/consumers/odr. We are not obliged and not willing to take part in dispute resolution proceedings before a consumer arbitration board.

15. Governing law and jurisdiction

These terms are governed by Estonian law, without prejudice to any mandatory consumer‑protection rights you may have under the law of your own country of residence. Where you are acting as a business (not a consumer), the courts of Estonia have exclusive jurisdiction, to the extent permitted by law.

16. Severability

If any provision of these terms is found invalid or unenforceable, the remaining provisions continue in full force, and the invalid provision will be replaced by one that most closely reflects its intended purpose.