Around 5.4 million tax payers have less than a month to complete their annual tax return, ahead of the self assessment deadline on 31 January.
HMRC says it expects 12.1 million tax returns to be filed this year. Around 55% of tax payers have already filed their returns, with more than 6.2 million choosing to submit online.
Those who have yet to file a self assessment return are being urged to act now; HMRC has said that it may be a more time-consuming process than anticipated.
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In fact, accountancy bodies have warned that both tax payers and accountants may struggle to meet this month's deadline because of the pandemic and many are hoping to see some leniency from HMRC when it comes to late filing penalties.
The Institute of Chartered Accountants in England And Wales (ICAEW) said: "Many member firms are under enormous resource pressure due to assisting clients with claims for COVID-19-related financial support and providing other pandemic-related business advice. While working every hour possible, they will still struggle to meet the filing deadline for all their clients."
Phil Hall, head of public affairs at the Association of Accounting Technicians (AAT), said: "Almost one million self-assessment tax returns, of the 11 million due, were filed late in the last financial year. As a result of the coronavirus pandemic, the situation will probably be much worse this year and late filings will rise dramatically."
Karl Khan, HMRC's interim director general for customer services, said:
"In what was a very difficult year for many, we are grateful to the 55% of our customers who have already submitted their returns.
"HMRC is ready to offer support to those who are yet to file their returns or are worried about paying their tax bill, but they must act now so we can help before the deadline."
Once customers have completed their tax return, and know how much tax is owed, HMRC says they can set up their own payment plan to help spread the cost of their tax liabilities, up to the value of £30,000. They can use the online Time to Pay facility to set up monthly direct debits. However, interest will be applied to any outstanding balance from 1 February 2021.
As ever, tax payers must be aware that if someone calls, emails or texts claiming to be from HMRC - saying they can claim financial help, are due a refund or owe tax - it might be a scam.
Written by Rachel Miller.