Many won't need reminding but a tax payment deadline is rapidly approaching for the UK's army of self-employed people and those with earnings outside of PAYE.

HMRC's second payment on account is due by July 31 affecting 4.8 million registered as self-employed.

David Redfern, director of DSR Tax Claims, urged those affected to ensure the payment is made ahead of next week's deadline or risk being penalised by HMRC.

Payments on account are used by HMRC to obtain tax revenue for the current tax year, prior to the submission of a self assessment tax return. Self-employed workers make two payments to HMRC, one on 31 January and one on 31 July, in respect of their tax bill for the current tax year, based on how much tax they were liable for in the previous tax year.

David Redfern said: "The 31 January deadline is familiar to most who are required to submit self assessment tax returns, but not so many people are aware that they are required to make payments on account with regard to the current tax year. Miss this deadline and you risk a penalty of 5 per cent of your unpaid tax bill."

He added: "If your income this year is substantially less than your income last year, get in touch with HMRC as soon as possible and you should be able to reduce your payments on account to more accurately reflect your income in this tax year.

"Similarly, if you are having difficulty in paying this second payment on account contact HMRC as soon as you can - you may be able to avoid a penalty if you keep HMRC informed and work with them to pay what you owe. Burying your head in the sand, however, will only escalate the problem."