If you are under 26 years of age you can renew your railcard:
Online: Go to www.16-25railcard.co.uk/, log into your account, then go to 'Renew Railcard'. You can only renew your 3-year Railcard online, however.
By Phone: 08457 48 49 50
In Person: At your nearest rail station ticket office. You'll need to complete the application form, and take your existing Railcard and Photocard. These will automatically be accepted as proof of age.
If you are over 26 years of age:The application form has to be verified by the University. Please come to the Student Information Desk in the Campus Centre and the form can be signed, a passport sized photograph is not required for a renewal.

As the Student Information Desk is closed on campus due to Covid-19 - mature students can apply online for their railcard

https://www.16-25railcard.co.uk/help/faqs/mature-student/

Please request a status letter from SiD and we will email this directly to your student email account. You will then need to forward the the status letter, the form and a copy of your ID to railcardhelp@nationalrail.co.uk who will then respond.