Originally Posted by
tlamdweeb
You can claim back the difference between HTD/GYH payments received and the HMRC rate, provided your assignment was for 2 years or less. Even if your assignment is subsequently extended, you can still claim. The key principle is that you expected, on the basis of the original assignment, that you would only be working at a particular location for 2 years: so you didn't up sticks and move house (say). Check your JPA assignment order before you claim.
One SiL does this. It is generally easier for ground branches than aircrew. If you are on a posting away from your type-base then again easier.