Pet Travel Scheme - The Pet Travel Scheme (PETS) is the system that allows pet animals from certain countries to enter the UK without quarantine as long as they meet the rules. It also means that people in the UK can, having taken their pets to these countries, bring them back without the need for quarantine.
The Pet Travel Scheme (PETS) applies to pet dogs and cats (including guide and hearing dogs) that are resident in either the United Kingdom or one of the PETS qualifying countries. Animals which meet the PETS rules can enter (or re-enter) the UK without having to undergo 6 months quarantine. Animals which do not meet all the rules must be licensed into quarantine. They might then be able to obtain early release if they can be shown to comply with the necessary PETS requirements.
Your pet may not enter the UK under PETS until six months have passed from the date that your vet took the blood sample which led to a successful test result (see below). Once the vet has signed the PETS certificate and that six month period has passed, the PETS certificate is valid and your pet may enter the UK.
More information is available from at The Department for the Environment, Food and Rural Affairs (DEFRA)