Privacy policy

The short version

• You photograph a letter. The photo is sent to our server once, read by an AI model, and the explanation is sent back. The photo is not stored on our server.
• Explanations, saved letters and reminders live on your phone. We do not have them.
• There is no account, no advertising, no analytics and no tracking across apps or sites.

What is processed, and where

Photos of letters. When you ask for an explanation, the pages you photographed are sent over an encrypted connection to our server, run by Vercel in Frankfurt, Germany, and from there to Anthropic’s API, which runs the model that reads the letter. Our server does not write the photos to disk. Anthropic processes them under its commercial API terms, which do not allow using customer data to train models; see Anthropic’s privacy policy for its retention periods.

Your language and country. The language you chose and, if you set it, the country you live in travel with the request so the explanation fits. Nothing else about you is sent.

A device id. The app creates a random identifier when it is first opened and sends it with each request. It lets us apply fair-use limits per install. It is not linked to you, your Apple ID or your phone’s identifiers, and a reinstall creates a new one.

Server logs. For each explanation our server logs the time, the duration, the token counts, the computed cost and the device id. Logs do not contain the letter or the explanation. Vercel keeps them for a limited period; we do not export them.

What stays on your phone

Saved letters, their first-page thumbnails, explanations, archive state, calendar events you add and reminders you switch on are stored only on your device, under Apple’s standard app protection. Deleting a letter in the app deletes it from your phone. Deleting the app deletes everything.

If you add a deadline to your calendar or switch on reminders, the app asks iOS for permission first and uses only the calendar and notification features of your phone.

Legal basis and your rights

Processing happens because you ask for it: it is necessary to provide the service you request (GDPR art. 6(1)(b)). Because we keep no copy of your photos or explanations, there is nothing for us to correct, export or delete on your behalf; everything is under your control on your phone. If you have a question or a complaint about how your data is handled, write to us at the address below. You also have the right to complain to your local data-protection authority.

Letters often contain personal data

An official letter usually carries your name, address and reference numbers, and sometimes health, financial or legal details. You decide what you photograph. If a letter concerns someone else, make sure you are allowed to have it read.

Children

Letter is meant for adults handling their own official mail. It is not directed at children under 16.

Changes

If this policy changes, the new version appears here with a new date. Material changes are also mentioned in the app’s release notes.

Contact

Letter is made by David Bastian, Barcelona, Spain. Questions about privacy: hello@useletter.app.