His nationality is United Kingdom but now he's living and working in Vietnam. He'll return to the UK for a short time (just about a month) and then come back to Vietnam for a year.
I intend to ask him to do me a favor by purchasing some shoes in the UK (then bring them back to VN) and reclaim the VAT but we are not sure if he can claim it back because of his nationality.
Could you give any suggestion about this case?
Nationality is not a problem. A friend of mine who is a UK national went back to the UK this summer and he had no problem claiming back the VAT on his purchases upon leaving the UK.