Time is running out for the collection of Gift Aid claims backdated to 2000.
The Institute of Fundraising is contacting all of its members to warn them that the first deadline for claiming backdated Gift Aid is approaching.
It is urging them to submit their claims for tax relief on donations to HM Revenue & Customs as soon as possible.
Gift Aid can be claimed up to six years after the date the donor makes the declaration, provided the donation was made after 6 April 2000.
Any charity can a make backdated claim, but the deadlines vary according to the type of organisation. A charity that is a registered company must make any claim within six years from the end of the accounting period to which the claim relates, whereas a charity that is classified as a trust for tax purposes must make any claim within five years of 31 January in the year following the end of the tax year to which the claim relates.
Megan Pacey, director of policy and campaigns at the Institute of Fundraising, said charities should make the most of the approaching deadline. "This presents an excellent opportunity to re-engage with supporters who haven't already signed up to Gift Aid and ask them to maximise their donations," she said.