Sub-processors
As of 17 October 2026. Convenience translation; the German version prevails.
These providers process personal data on our behalf when you use Kalender Sync. This list forms part of our data processing agreement, which references it rather than embedding a copy.
The Kalender Sync application, database and backups are located in Germany. Providers based outside the EU process data on the basis of the EU Standard Contractual Clauses (Art. 46 GDPR). The technical and organisational measures and the deletion periods are set out in the data processing agreement.
| Provider | Purpose | Processing location | Safeguards |
|---|---|---|---|
| Hetzner Online GmbH Industriestr. 25, 91710 Gunzenhausen, Deutschland | Hosting of the application and database; encrypted backups | Germany (application and database: Nuremberg; backups: Falkenstein) | DPA under Art. 28 GDPR |
| Lettermint B.V. Willemsvaart 16 B, 8019 AB Zwolle, Niederlande | Sign-in codes, transactional email and service notifications | Netherlands, EU | DPA under Art. 28 GDPR |
| Peaberry Software, Inc. (Customer.io) 9450 SW Gemini Dr., Suite 43920, Beaverton, OR 97008-7105, USA | Customer service email, onboarding and trial notices (from 13 Oct 2026); no calendar content | EU data region; access from the United States possible | DPA under Art. 28 GDPR; EU Standard Contractual Clauses |
| Sendinblue SAS (Brevo) 9-17 rue Salneuve, 75017 Paris, Frankreich | Historical contact, suppression and delivery records until the migration is complete; active sending switched off | France, EU | DPA under Art. 28 GDPR |
Changes and objections
We announce new or replaced sub-processors at least 30 calendar days before use, by email to the address of your account. How you can object is set out in section 7 of the data processing agreement. Questions or objections: support@kalender-sync.de
Not sub-processors
Calendar services you connect. Google (Google Ireland Ltd., Google Calendar API), Microsoft (Microsoft Ireland Operations Ltd., Microsoft Graph API), Apple iCloud, GMX, WEB.DE, mailbox.org, Infomaniak and other CalDAV or iCal services are the calendar services you choose and connect yourself. We access them only within the connections you set up; calendar data flows only between your own accounts. Your contract with the respective provider governs (for Google and Microsoft, among others, the EU-US Data Privacy Framework or Standard Contractual Clauses).
AI assistants you connect. If you connect an AI assistant (such as Claude or ChatGPT) through the MCP interface, its provider is a recipient at your instruction and not our sub-processor. Nothing is transferred without your per-calendar approval.
Services for our own purposes. Payment processing through Stripe Payments Europe Ltd. (Ireland; with transfer to Stripe, Inc., USA, on the basis of the EU-US Data Privacy Framework or the Standard Contractual Clauses), hosting of this website at Netlify, and website analytics and ad measurement do not process customer data on your behalf. We use them as controller; the privacy policy gives details. System monitoring and logging run on our own infrastructure without any further service provider.
Earlier versions of this list are available on request. Deutsche Fassung
