HMRC issues urgent tax message as households face instant £100 fines

His Majesty's Revenue and Customs (HMRC) has issued an urgent tax message to households as a vital deadline is looming.

The government department has said there is now just under 100 days to go before households need to file their tax return and pay any tax owed before 11.59pm on January 31, 2026, with those who miss the deadline facing an instant £100 fine. According to HMRC, more than 3.5 million people have already filed their Self Assessment tax return for the 2024 to 2025 tax year, but with the January deadline now looming, households yet to do their return are being urged to file it early.

HMRC said those who start their return early can go back to it as many times as needed before submitting it and filing early also means households will know how much tax they owe sooner, allowing them time to prepare to pay their bill by the deadline.

The deadline for paper tax returns for the 2024 to 2025 tax year is October 31, 2025, but online filers have until January 31, 2026.

Myrtle Lloyd, HMRC's Chief Customer Officer, said: "With 100 days to the Self Assessment deadline, now is the time to get started.

"Completing your return now means you know how much tax you need to pay ahead of the deadline. We are here to help with lots of help and advice, just search 'file a tax return' on GOV.UK to find out more."

Paying your tax return on time avoids any potential penalties and interest as HMRC charges a late payment penalty of £100 from the day after the deadline.

After three months, those who still haven't filed their tax return face an additional penalty of £10 per day, up to a maximum of £900. This increases yet again after six months with a further penalty of 5% of the tax that is due, or £300 - whichever is higher. After 12 months, another 5% - or £300 - will be added.

As such, this takes the total fines in late payments over a period of 12 months up to a hefty £1,600, plus interest on the amount that is owed.

Payments must be made within 30 days of the date on the penalty notice and you can appeal against a penalty if you have a reasonable excuse.

HMRC said: "If you send your tax return late you'll get the following late filing penalties:

• an initial £100 penalty
• after 3 months, additional daily penalties of £10 per day, up to a maximum of £900
• after 6 months, a further penalty of 5% of the tax due or £300, whichever is greater
• after 12 months, another 5% or £300 charge, whichever is greater

"To avoid this, send your Self Assessment tax return as soon as possible. All partners will be charged a penalty if a partnership tax return is late.

"If you pay your tax late you'll get penalties of 5% of the tax unpaid at:

• 30 days
• 6 months
• 12 months

"You'll also be charged interest on the amount owed. To avoid this, pay your Self Assessment tax bill as soon as possible."