The Institute of Fundraising has criticised the government’s planned Gift Aid Small Donations Scheme for being too bureaucratic.
It will enable charities and community amateur sports clubs to claim, from April, a top-up payment at a rate equivalent to Gift Aid on small donations of £20 or less totalling up to £5,000 in a year.
In its response to the consultation, the IoF warns that unless the criteria are changed its target of helping 100,000 organisations to benefit will not be hit.
Peter Lewis, chief executive of the institute, said: "The government must be commended for trying to help small charities with the GASDS, but unfortunately its best intentions may be undermined by the detail of these proposals.
"The plans are far too complex and bureaucratic and are likely to turn off small charities from participating in the scheme and boosting their incomes."
The IoF said the proposed requirement that charities must have a record of at least three years of making Gift Aid claims before they are eligible would mean many organisations would be unable to benefit.
"I can fully understand the government is concerned about fraud, but there are other measures that could be used to check legitimacy and financial probity," said Lewis.
"A key driver behind the GASDS was to help those small charities that did not or were unable to claim Gift Aid – so in effect these plans could be self-defeating."
The real losers, he said, might be the small community projects that the scheme was supposed to help.
In its response, the IoF said the charities that would benefit most would be the least eligible.
"Large charities that already claim Gift Aid will benefit from the scheme, which is positive, but unless the qualifying conditions are relaxed, the scheme is likely to fail to have a significant impact on the sector as a whole," it says.