When setting up the Singpass app on your device, you will be issued a digital identity by the National Certification Authority (NCA). This is used as proof of your online identity whenever you transact with Singpass.

Your digital identity is represented by the authentication certificate issued to you. It comes with a unique serial number that can be seen in your Singpass app settings, under "Digital identity details".

The authentication certificate is valid for 1 year in Singpass app. Once it expires, you will be prompted to renew the authentication certificate. You can proceed to renew the certificate, in order to continue using the Singpass app.