The Institute of Fundraising has criticised a local authority policy introduced to ensure at least 70 per cent of income from charity clothing collections goes to charitable causes.
A new policy on issuing permits to run house-to-house collections from Corby Borough Council says "serious consideration" should be given to refusing an application if less than 70 per cent of income from the collection would go to charity.
Louise Richards, director of policy and campaigns at the Institute of Fundraising, said the 70 per cent figure was arbitrary because costs varied so much between different clothing collections.
"Local authorities have to be careful about this type of blanket policy," she said.
"It’s their right to have this policy in place, but it could run into problems by stopping legitimate charity collections."
IoF guidance on house-to-house collections does not include any recommendations on whether charities and third parties running collections should set a percentage split of income.
Damian Wilkins, health protection manager at the council, said councillors thought it would protect local residents.
"It’s to tackle the issue of collectors who say they will give some of the income to charity but it ends up being a very small percentage," he said. "Sometimes it’s as low as 8 per cent."
He said the policy would be reviewed if there was a significant fall in donations.
Wilkins said other boroughs in Northamptonshire were looking to introduce similar policies.