Building your app
Privacy policy
A privacy policy is a public page saying what personal data your app collects and who receives it.
Also called privacy notice
App stores can reject an app without one, and many privacy laws expect one once you collect even an email. In the European Union the data protection rules are the GDPR (General Data Protection Regulation), explained on the European Commission's data protection page (read 2026-10-06). This is not legal or tax advice, check with a lawyer or accountant.
When this shows up
Example, not a real founder: you submit your app to an app store and it comes back rejected. The reviewer could not find a privacy policy link, and your sign-up form collects email addresses.
What to do next
List every piece of personal data your app collects and every outside service that receives it. Use that list as the base of your policy, then have a lawyer read it.