It differs from country to country, so you're best to get your own local tax advice. We advise you to look at your own government's tax regulations to make sure you have all information about anything related to tax.
Capital gains tax may be payable on the proceeds of sale of a Membership, and You are solely responsible for any tax You may incur in respect of Your Membership, including capital gains tax which may be payable on any proceeds of sale of Your Membership.