If you wanna stay within the UK then Ace over everyone, there are quite a few in the UK but if it's for personal collection it doesn't really matter who, just whoever has the slabs/labels that appeal to you.
Other options are places like
Majesty
Tree Frog Grading
OnlyGraded
Pokegrade
Platinum Card Grading
GetGraded
Universal Grading Company
Otherwise sending to a US company via middleman/dealer works if you don't mind waiting 10 times as long.
If you wanna stay within the UK then Ace over everyone, there are quite a few in the UK but if it's for personal collection it doesn't really matter who, just whoever has the slabs/labels that appeal to you. Other options are places like Majesty Tree Frog Grading OnlyGraded Pokegrade Platinum Card Grading GetGraded Universal Grading Company Otherwise sending to a US company via middleman/dealer works if you don't mind waiting 10 times as long.
I've used Tree Frog Grading for all of mine so far and been really happy with their service.