UK issued EU pet passports anr no longer valid for travel to the EU, the UK has been placed as a part 2 listed country which means your pet now requires a Animal health certificate (AHC)
Your cat /dog must be at east 12 weeks old to be vaccinated.and have a working microchip and a valid rabies vaccination meaning 21 day must have past before travel you should take your pet to your Veterinarian but first ensure they can issue the AHC
The certificate is valid for 4 months after issue for onward travel within the EU and can be used for re entry to the UK up to 4 months. You must get a new AHC for each trip out of the UK . it is only valid for departure 10 days after it is issued.
your pet is moving abroad once you hold an address we advise you to get an EU pet passport for any further travel to and from the UK the AHC will no longer be required. This can be sourced for a domestic Veterinarian