New year finances. If you blow your cash over Christmas and are planning to pay your self-assessment tax bill (due no later than 31 January 2018) with your credit card you’ll be out of luck. HMRC won’t accept credit card payments after 12 January 2018. This goes for all tax payments, not just those for self-assessment.
Tip. If you were relying on paying a tax bill due on or after 13 January by credit card, e.g. your PAYE bill for December, you’ll either have to pay earlier or make other arrangements.