How can a British national be considered as an overseas when applying to uni, how can he become national?

My friend was born in the UK, stayed there for, i think more than 8-9 years, but went oversesas for about 5-6 years. now he wants to go back to uk, will he be considered as oversesas, if yes, then how and why?? (since he was born there, he had stayed there, and also has residence there) If he is considered as overseas, how can he become national for applying for university in 2014.