u/JayneLut

https://www.electoralcommission.org.uk/voting-and-elections/ways-vote/apply-vote-proxy

Details on how to apply are on this webpage from the Electoral Commission.

Registered to vote, but not going to be able to do so in person? Missed the deadline to register for a postal vote/ postal vote not arrived yet? You have until 5pm today to complete a form and email it to Cardiff Electoral Services - ElectoralServices@cardiff.gov.uk