HM Revenue and Customs (HMRC) is to stop accepting payments by credit card from 13 January - less than three weeks before the deadline for self assessment tax returns.
This means that anyone planning on paying their tax bill this way now has less than a month to file their return.
This change could have a significant impact, as more than 800,000 tax payments were made by credit card in 2015-16.
Here, we explain how the new rules will work, and what you can do if you're struggling to pay your self-assessment bill.
While personal credit cards will no longer be accepted, corporate and business cards won't be affected.
The change is the a result of a new directive that will ban companies from charging a fee when customers use Mastercard and Visa credit cards.
As it stands, many companies demand a surcharge for credit card payments to cover their processing fees - and HMRCreceiveda total of £13.2m in credit card surcharges in 2015-16.
From 13 January, however, companies will either have to foot the processing bill themselves or stop accepting credit card payments.
For example, the Driver and Vehicle Licensing Agency (DVLA) - which currently charges £2.50 to use a credit card - will still accept such payments, albeit without the surcharge.
Payment times vary, from online banking (same or next day) to new direct debits (up to five working days), so whichever method you choose, you'll need to ensure the money reaches HMRC by the deadline.
This could mean setting up an instalment plan by direct debit, which will allow you to pay your outstanding bill on agreed dates.
Over nine million people in the UK have to complete a tax return.
You'll need to file one if you're self-employed (sole trader, business partner or director), have an annual income of £100,000 or more or if you have a pre-tax investment income of £10,000 or more.