The Institute of Chartered Accountants in England and Wales (ICAEW) is “urging” taxpayers who have yet to submit their Self-Assessment for 2017/18 to do so “immediately”.

In it’s new report, the ICAEW said business owners and self-employed traders only have until the end of April to complete their tax return or risk “additional daily fines”.

The penalties for not completing the Self-Assessment return by 31 January – the official final online deadline – is an automatic £100 fine.

However, if the return is submitted any later than 30 April 2019, an additional penalty of £10 per day, up to a maximum of £900, will be due.

If it is still not complete six months after the initial deadline, a further penalty of five per cent of the tax due or £300, whichever is greater, will be due, followed by a second five per cent penalty if no submission is made after 12 months.

The report comes after the ICAEW revealed that almost 700,000 taxpayers missed the online Self-Assessment deadline in January.