According to the figures, released by HM Revenue and Customs (HMRC) around 1 million people missed the self-assessment deadline.
Those who have missed the self-assessment deadline now face a £100 fine which will net HMRC and “estimated £100 million in automatic fees.”
HMRC received 11,489,825 returns by the 31 January 2026 deadline, this includes voluntary returns and late registrations.
Charlene Young, a senior pensions and savings expert at AJ Bell, said, “An estimated one million people failing to file could net HMRC £100 million in automatic fees alone.
“There is an automatic £100 fine for late filing.”
Young added, “If you don’t have an excuse to appeal a fine but still owe money, you might still be able to set up a payment plan to get back on track.
“It’s essential you don’t put your head in the sand.”
Myrtle Lloyd, HMRC’s chief customer officer, said, “Thank you to the millions of people and agents who filed their self-assessment tax return and paid any tax owed by January 31.
“Anyone who missed the deadline should file their return as soon as possible, as penalties and late payment interest may be charged.”
