Thousands of contractors have been fined for failing to file their CIS tax returns by the deadline.

More than 86,000 penalty notices have been sent to 37,000 contractors who missed the 19 October date for filing their returns.

Contractors will be fined at least £100 for every late monthly return, a sum that rises with the number of subcontractors involved. This means that the total amount of fines will be more than £8.6m.

The notices come after the Construction Confederation called for a stay of execution on fines for late returns after the postal strike.

Liz Bridge, director of tax at the Construction Confederation, urged contractors who had sent their returns on time to appeal.

She said: “My experience in London is that the effects of the postal strike are not over, but HM Revenue and Customs is saying it doesn’t believe its office in Netherton has arrears. If there are people who received notices and have posted their returns, they must appeal, appeal, appeal.”