As i understand it it is not in the remit of the BPA to inspect herds, however in the case of pig identification they do send breed reps to check ear numbers and clarify that a pig registered is indeed that pig.
The main people for inspecting are Animal health & was trading Standards but don't know if this will change as they no longer look after AML's. Most inspectors are helpful and and they are just making sure you are dotting the i's and crossing the T's.
HTH
Mandy