Overdue tax returns: You have until 30 April to get last year's forms in or face additional fines

Some 890,000 people missed the cut-off and faced an instant £100 fine

Anyone who missed the January tax returns deadline has until Thursday to get their last year's forms in or be hit with additional fines. Some 890,000 people missed the cut-off and faced an instant £100 fine.

"Late tax returns have already earned HMRC £89m so far this year," said Anita Monteith, tax manager at the Institute of Chartered Accountants in England and Wales. "Any latecomers after 30 April could face additional fines of £10 a day. It quickly adds up. The additional fines could reach £900, leaving people with a total bill of £1,000 by the end of July.

"What's more, anyone who hasn't complied by then could face an additional penalty – 5 per cent of the tax due or £300, whichever is greater." If you haven't submitted your 2013/14 return yet, you should send it online – if you send in a paper return, the penalties will be even higher, as the deadline for paper returns was 31 October 2014.

"If you have a 'reasonable excuse' for filing your tax return late you shouldn't face penalties, but you will need to provide evidence of the circumstances," Ms Monteith added.