About �300m was raised in the UK after the tsunami

Gift Aid means charities can claim an extra 28p from the government for every pound they receive but phone donors must consent to this in writing.

The Disasters Emergency Committee feared having to send 1.2 million letters to donors seeking confirmation.

But the DEC will now be able to notify donors through letters it had already planned to send about its relief work.

Chancellor Gordon Brown had ordered talks between the DEC and HM Revenue and Customs (HMRC) officials on Monday to sort the problem out.

It had been reported charities could miss an extra �9m.

'Streamlining'

A Treasury spokeswoman said: "Because of the scale of the tsunami disaster and the public's response to it, HMRC is keen to do everything it can to ensure that the money donated by the British people reaches the people who need it most, as effectively as possible.

"It was agreed that the notification that HMRC needs to be sent to donors can now be included in a letter that the DEC had already planned to send to its phone donors, updating them about work being done in the field.

"This represents a streamlining of communications which is in the interest of both the DEC and the HMRC.

"It will fulfil the DEC's commitment to build good relations with donors. It will also enable HMRC to meet its legal obligations in administering the Gift Aid scheme.

"The extraordinary scale of the response to the tsunami appeal has presented us with an opportunity to redefine the giving procedures to gain maximum benefit from charity donations.

"HMRC is committed to providing practical support to all charities across the entire range of tax-efficient charitable giving."

A DEC spokesman confirmed the meeting had resolved the committee's concerns.

He said: "Reporting back to donors is extremely important to us, and claiming Gift Aid is also extremely important because it is worth a lot of money.