What do the different codes mean?

Mobile Pass Number/Pass Number

This is a combination of six digits and letters (e.g., XT542R) that you use to activate your Interrail Pass.

Pass Cover Number/Verification Number

This is a code that starts with a capital "I" followed by eight digits (e.g., I87654321) that you use to reserve seats directly with train operators.

Passport/ID Number

This is the code on your passport (identity document) or national ID card. You can travel with either option, but check which countries allow you to travel with a national ID card.

Pin Code

The app may ask you to verify your identity with a PIN code. This is the same PIN code you use to unlock your mobile phone.