The Vehicle Builders and Repairers Association (VBRA) has warned its members that many are not taking advantage of available reductions in the climate change levy (CCL).
The VBRA said the levy could be costing them hundreds of pounds when reductions of up to 80% were possible.
The charge was introduced on gas and electricity bills from April 2001.
VBRA director general Ron Nicholson said: "The responsibility for obtaining the reduction seems to be falling between departments: the bodyshop manager and the accountant each thinking it is the other's duty to recover the tax.
"In many cases we are also finding there is complete unawareness that the climate change levy is being paid and of the reduction scheme.
"This is compounded where the bills are paid by direct debit and little or no notice is taken of the make up of the invoice. So, in effect, the tax has been introduced unnoticed."
The VBRA said all bodyshops, members and non-members could register for the reduction under its umbrella agreement with the government.
Only in this way could the body repair industry recover this tax, it said.
