Taxpayers have been left waiting nearly a month for refunds because of an error on the Revenue (HMRC) website.

The glitch on the online tax return form meant applications were mistakenly rejected when accountants entered their bank account details to receive a client’s refund. The fault has not been fixed since April 30, leaving many unable to pay tax or claim refunds.

The problem has been highlighted by an accountant from Kent, Sue Hitchcock, who has been in business for six years and prepares tax returns for about 700 clients working in the construction industry.

Her firm, Sub-Tax, specialises in obtaining tax relief for their business travel as they move around construction sites. She can get tax refunds ranging between £600-£3,000 a year.

Hitchcock said 40 of her customers were owed £100,000 between them and her own business was under threat as she wouldn’t be paid until they got refunds. “I’m extremely cheesed off,” she said.

A statement on the HMRC website describes the problem as a “service issue” and says it is being investigated “as a matter of urgency”.

Large accountancy or book-keeping firms that use commercial self-assessment software are not affected as the problem lies with the HMRC’s own software.