HM Revenue and Customs (HMRC) has confirmed that from January 31, 2026, households in the UK who fail to file their Self Assessment tax return on time will face strict financial penalties. An initial fixed penalty of £100 will be charged immediately after the deadline. If the tax return remains unfiled, additional daily fines of £10 will accrue for each day the return is late, up to a maximum of £900.
These daily penalties kick in three months after the January 31 submission deadline and continue until the maximum is reached or the return is submitted. Furthermore, if the return is still outstanding after six months, a further penalty of 5% of the tax due or £300 (whichever is greater) will be applied. After 12 months, another 5% or £300 charge will be imposed.
HMRC also issues penalties for late tax payments: 5% of the unpaid tax at 30 days, six months, and twelve months, plus interest on the outstanding amount. According to HMRC, all partners involved in a partnership must ensure timely filing to avoid penalties.
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Myrtle Lloyd, HMRC’s Chief Customer Officer, thanked the millions who filed and paid by the deadline and urged those who missed it to act promptly. She emphasized that using HMRC’s digital services is the quickest way to file returns and settle any outstanding tax.
To avoid penalties and additional interest charges, HMRC advises taxpayers to submit their Self Assessment returns and pay any amounts due as soon as possible.