Lifetime pension allowance and triviality limit

My wife is approaching 60 and has a private pension which was contributed to solely by the company that we are owner/directors of. The total value of the fund is likely to be below the triviality limit of £17500 for this year. So as I understand the rules, she may withdraw all the funds less a deduction for the tax allowance attributed to the payments during the lifetime of the pension fund. However, as I've pointed out, the pension was contributed to solely by our company and it was the company which received the tax allowance. So the question is, what amount of tax should be deducted from the fund, that paid at the personal rate or that paid at the corporation rate, which clearly was less?