It was not an approved HMRC share scheme. The shares were issued 3 years prior to the pay out based on company performance. We had an option to take the cash value or shares based on the vesting price of £6.60 per share. I took the shares. The amount of shares I received was after PAYE and NIC deductions.
I think this is how you would work out capital gains tax. My employer has taxed me on the whole benefit which is the share quantity * the share price. They issued them to me at the vesting price so there is no difference between the share value.
That is the bog standard position with unapproved share options. When exercised and sold at once, which is the norm, there is no gain to be taxed so in Capital Gains Tax terms the answer is the proverbial lemon.