The general rule with an Inland Revenue approved scheme is that the grant of shares or an option to acquire shares is not treated as an income receipt by the employee and there is no tax to pay. On the eventual sale of the shares, there will be, however, a potential charge to capital gains tax. The base cost from which the capital gain is calculated will be the price paid by the employee for the shares.
Why is it winding up. Normally you have the option to buy at the opening, closing or average price over the life of the scheme. What is winding up here, the saving or the share holding?
I may be able to help. It has been a while since I studied this though.
What type of scheme, why winding up etc.
If you want PM me instead
http://www.direct.gov.uk/en/MoneyTax...ax/DG_10022224
lists the different scheme types.