---
title: "Was wissen sie?"
url: "https://divergenz.ch/projects/waswissensie/"
language: "en"
description: "An online service for data access requests in Switzerland: find an organization, add your details, and download the request as a PDF or have it sent by mail."
---

# Was wissen sie?

An online service for data access requests in Switzerland: find an organization, add your details, and download the request as a PDF or have it sent by mail.

Project: Online service for Swiss data access requests

Contribution: Product concept · Interaction design · Prototyping

Technologies: [TanStack Start](https://tanstack.com/start/latest) · [React](https://react.dev/) · [TypeScript](https://www.typescriptlang.org/) · [Cloudflare Workers](https://www.cloudflare.com/products/workers/) · [Cloudflare D1](https://developers.cloudflare.com/d1/) · [Cloudflare R2](https://developers.cloudflare.com/r2/) · [Primer](https://primer.style/) · [pdf-lib](https://pdf-lib.js.org/) · [Stripe](https://docs.stripe.com/) · [Pingen](https://api.pingen.com/documentation)


## Your right to access your data

Swiss data protection law gives you the right to find out what personal data
companies, organizations, and government agencies are processing about you. To
exercise this right, you must submit a data access request to the relevant data
controller.

With [“Was wissen sie?”](https://waswissensie.ch/), we have developed an online
service to help you with this. You can create your request in a few steps and,
if needed, have it printed and sent by mail.

## From search to finished letter

First, search for the organization in the Swiss UID Register and select it as
the recipient. Then enter your name and mailing address. An address search helps
you find Swiss addresses.

If necessary, add details such as your email address, cell phone number, or
customer number so the organization can identify you. You can also attach a copy
of your ID. You can black out any information that is not necessary for
identification.

In the preview, you can review the finished letter and add or correct your
information before sending it.

## Download as a PDF or send by mail

You can download the request as a PDF, print it, and send it yourself.
Alternatively, “Was wissen sie?” can handle the printing and mailing for a fee.
You can choose between A-Post Plus and registered mail so that delivery is
documented.

## For data controllers in Switzerland

The service is currently for people in Switzerland and supports requests to data
controllers listed in the Swiss UID Register. This register includes many, but
not all, companies, organizations, and government agencies.

For foreign online services, a Swiss subsidiary is often not the data controller
under data protection law. Therefore, a listing in the register alone does not
mean that it is the correct recipient. Individuals outside Switzerland are not
currently supported directly.

Attorney Martin Steiger helped us with data protection issues related to the
service. In his
[article on “Was wissen sie?”](https://steigerlegal.ch/2026/06/18/auskunftsbegehren-schweiz-waswissensie/),
he describes the process and the current limitations of the service.

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[Deutsch](https://divergenz.ch/de/projekte/waswissensie/)