If SIPP reaches lifetime allowance by investment performance

[david66]

Suppose I am an incredible investing whizz and 60 years old. I have ceased contributing to a SIPP which has £400K in it. Then the following year I make a 50% return on the money in the SIPP by canny stock market trading. What are the tax implcations for the investment returns? How are they treated?

Also if I keep doing this (I know unrealistic ) what happens when I exceed the lifetime allowance?

Many thanks in advance.

[AGoodman]

As matters stand, the lifetime allowance is being removed form 6 April (absent the collapse of the Govt between now and the Finance Bill being passed). The cap on tax free lump sums will remain.