Gift Aid can be claimed against any cash donation, and from the proceeds from any item donated to the school for sale on ebay. The scheme operates in accordance with the following rules from H.M. Revenue and Customs

Your charity can act as an agent for a prospective donor by selling goods on their behalf in the hope of having the proceeds (money) donated under Gift Aid.
For any eventual donation to qualify:
  • the goods must remain the property of the potential donor until they are sold - it’s the donor who is selling the goods not your charity.
  • the donor must have the right to keep all or part of the proceeds of the sale.
  • your charity must contact the donor after a sale has been made and offer to pay them the proceeds from the sale of their goods.
  • if the donor chooses instead to donate some or all of the money to your charity this will be a straightforward donation of money to you and can therefore be Gift Aided.
  • your charity must keep a record of the proceeds of the sale being offered to the donor along with their decision to gift them to you e.g. an exchange of correspondence.
  • if you ask the donor to complete a Gift Aid declaration before the sale (in anticipation of the proceeds being gifted to you) the wording of that declaration must not commit the donor to making a donation – the donor must retain a choice.
You can can use Gift Aid if the amount of tax they have paid in the tax year of the donation is sufficient to cover the amount of tax the charity will reclaim against the donation. The tax paid by the donor may be Income Tax, Capital Gains Tax or tax credits on UK company dividends. Tax years start on 6 April and run until 5 April the following year.

A gift aid declaration form, for cash donations, can be found here.

A gift aid declaration form, for donated items, can be found here  (Microsoft Word)     (PDF)