More than 11.5m people filed their self-assessment tax returns on time but an estimated 1.1m people missed last Friday’s deadline, HMRC has said.

Some 11,509,810 returns were received by the midnight deadline on 31 January with 732,498 people filing their return on deadline day.

Thousands submitted their return with minutes left to go, with 31,442 returns filed between 11pm and 11.59pm.

HMRC said anyone who has missed the deadline should file their tax return now and pay any tax owed.

Myrtle Lloyd, HMRC’s director-general for customer services, said: “I’m urging anyone who missed the deadline to submit their return as soon as possible to avoid any further penalties.”

Penalties include an initial £100 fixed penalty, which applies even if there is no tax to pay. The initial penalty can be followed after three months by additional daily penalties of £10 per day, up to a maximum of £900. After six months, there could be a further penalty of 5% of the tax due or £300, whichever is higher, and after 12 months another 5% or £300 charge, whichever is greater.

There are also additional penalties for paying late – 5% of the tax unpaid at 30 days, six months and 12 months. Interest will also be charged on any tax paid late, HMRC said.

Charlene Young, pensions and savings expert at AJ Bell, said: “The numbers show that the perfect storm of rising interest rates, reduced allowances and frozen tax thresholds in 2023-24 continued to whisk people into the tax return trap.

“HMRC estimates that 1.1m people failed to file by the deadline risking £100 late filing penalties, a potential windfall for the taxman of £110m.”

She said anyone who earned more than £150,000 for the year should have filed. “This earners trigger was one threshold that increased (up from the £100,000 for the previous year), but the starting point for additional rate tax (45%) was also slashed from £150,000 to £125,140 in April 2023, meaning those people who escaped having to automatically do a return would’ve still paid more in tax last year.”