Foreign commonwealth soldiers and veterans should be exempt from paying fees during naturalisation, life in the U.K. test, and language test as long as they have served for the minimum contract required and have qualified for the length of stay required.
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After serving in the British Army from commonwealth countries, you’re still required to undertake life in the U.K. test, language test and also pay the fee required for naturalisation. This is very sad after you have put your life on the line to serve in the queens army to defend the British well being.