Around 100,000 self-assessment taxpayers have set up payment plans to split the cost of their tax bills into monthly instalments in 2021/22.
Individuals have paid over £310 million in manageable instalments using time-to-pay arrangements since April 2021.
The online service can be set up for up to 12 months if an individual has a tax debt of up to £30,000, or is struggling to pay.
For payments relating to the 2020/21 tax year, HMRC has given taxpayers until 1 April 2022 to set up such an arrangement or pay their liabilities in full.
Myrtle Lloyd, HMRC's director-general for customer services, said:
"We understand some customers might be worrying about paying their self-assessment bill this year, and we want to support them."
Anyone who did not file their 2020/21 tax return by 31 January 2022 will not receive a late-filing penalty if they file by 28 February 2022.
Since 1 February 2022, all outstanding tax bills have been subject to interest at 2.75%.
Talk to us about any aspect of self-assessment.