It is part of consultations by the Fostering Network on what a minimum allowance for foster carers should cover.
Vicky Swain, campaigns manager at the network, said: "The issue causes fights between carers, social workers and children." Other issues up for debate include what is a reasonable clothing allowance and what the costs of extra-curricular activities should be.
The Fostering Network and the Association of Directors of Social Services will also survey local authorities to determine how much it will cost to implement the network's recommended minimum allowances for carers.
A late amendment to the Children Act 2004 introduced a minimum allowance for foster carers in England and Wales. Children's minister Margaret Hodge has said she will wait until 2007 before she considers using the power (Children Now, 12-18 January).
