You can earn 100k without loosing your personal tax allowance. The FRE is separate. Once over 100k you loose your personal allowance in a sliding scale. The trick is that everything you put into your pension is not counted up to your annual allowance. You can put 40k a year into a pension, so if you earn 140k and put 40k into your pension you keep all your allowance. After that....well lucky you, go part time.