UK taxpayers face a major expansion of HMRC penalties 2026/27, with higher interest charges, a new submission regime and tougher fines. HMRC’s April 2026 Employer Bulletin confirms the changes have materially increased the cost of missed deadlines.
Key figures at a glance:
- Late payment interest stands at 7.75% per year (base rate of 3.75% plus a widened 4% margin).
- A new MTD points-based penalty system triggers a £200 fine once four late submission points are reached.
- HMRC stepped late payment penalties charge 3% at day 15, a further 3% at day 30, plus 10% per year thereafter.
- Failure to notify HMRC of taxable income can attract penalties of up to 200% for offshore matters.
- Crypto exchanges began sharing UK customer data with HMRC under CARF from 1 January 2026.
Why HMRC penalties have increased
The expansion of HMRC penalty rates 2026/27 reflects two converging policy shifts. The government announced at Autumn Budget 2024 that it would widen the margin on late payment interest.
From 6 April 2025, HMRC late payment interest moved from base rate plus 2.5% to base rate plus 4%, as confirmed in GOV.UK’s published interest rate tables. At the current base rate of 3.75%, that produces an annual charge of 7.75% on overdue tax.
Repayment interest — the rate HMRC pays on overpaid tax — sits at just 2.75%. The asymmetry is deliberate, making late payment considerably costlier than before.
The second shift is Making Tax Digital for Income Tax, live from 6 April 2026. Self-employed individuals and landlords earning above £50,000 are now required to keep digital records and submit quarterly updates.
Late filing penalties for Self Assessment
For taxpayers not yet within MTD, the existing late filing penalty Self Assessment regime continues to apply. A £100 fixed penalty is triggered the day after the 31 January deadline, even where no tax is owed.
After three months, daily penalties of £10 per day apply for up to 90 days, adding £900. At six months late, HMRC charges 5% of the tax due or £300, whichever is greater.
The same additional charge applies again at 12 months. Among HMRC penalties 2026/27, cumulative late filing fines alone can therefore exceed £1,600 before any tax owed is added.
How the MTD points-based penalty system works
Each missed quarterly update or tax return deadline adds one point to a taxpayer’s record. Quarterly MTD filers hit the threshold at four points; annual returns at two.
A £200 penalty is triggered when the threshold is reached, and each further late submission incurs another £200. These HMRC penalties 2026/27 represent a significant departure from the older fixed-fine model.
For the 2026 to 2027 tax year, HMRC is applying a soft landing. Penalty points are not charged for late quarterly updates, though they apply to the final declaration.
The full regime takes effect from 2027 to 2028. Voluntary early adopters face a stricter two-point threshold rather than four.
Points expire after a period of compliance: 24 months for annual filers and 12 months for quarterly filers. All outstanding submissions must have been filed for the clock to start.
HMRC stepped late payment penalty rates
HMRC introduced an HMRC stepped late payment penalty structure from 6 April 2025. If tax remains unpaid 15 days after the due date, a charge of 3% of the outstanding amount applies.
A further 3% is added at day 30, bringing the total to 6%. From day 31, an additional 10% per year accrues daily on any remaining balance.
These charges sit on top of the 7.75% annual late payment interest rate. Taxpayers who set up a Time to Pay arrangement before day 15 can avoid these penalties.
Bills under £30,000 may be arranged online without needing to contact HMRC directly. This is particularly relevant for freelancers and smaller landlords.
Failure to notify and inaccuracy penalties
A separate regime applies where a taxpayer does not tell HMRC about new taxable income. This covers self-employment, rental income, capital gains and crypto disposals.
For non-deliberate, unprompted disclosures, penalties range from 0% to 30% of unpaid tax. Prompted disclosures carry 10% to 30% of the amount owed.
Deliberate failures to notify HMRC attract 20% to 70% of the tax. Deliberate and concealed failures with a prompted disclosure can reach 50% to 100% of the amount owed.
For offshore matters, penalties may reach up to 200% of tax due. HMRC can assess up to 20 years of back tax where deliberate concealment is identified.
Inaccurate tax return penalty rates follow a similar structure. Where reasonable care is taken, no penalty applies; careless errors attract 0% to 30%, deliberate inaccuracies 20% to 70%, and deliberate concealment 30% to 100%.
Penalties for employers
Employers face HMRC fines 2026 for late submissions. Late P11D or P11D(b) filings attract £100 per 50 employees for each month late.
Late RTI Full Payment Submissions carry £100 to £400 per month, scaled by employer size. Issuing P60s after 31 May can result in fines of up to £300.
Late Class 1A NIC payment after the 22 July electronic deadline incurs interest plus potential penalties. General record-keeping failures can attract fines of up to £3,000 per year.
From April 2026, MTD digital record-keeping rules introduce further penalty exposure under the points system. Records must generally be kept for at least 22 months after the tax year for individuals, or six years for businesses.
The April 2026 Employer Bulletin reminds employers that late filing penalties are charged on a monthly basis. Penalty notices are issued each quarter until the outstanding return is received.
Crypto gains and CARF reporting risks
From 1 January 2026, UK-based crypto exchanges and custodial wallet providers began reporting transaction data under the Crypto-Asset Reporting Framework. The first reports are expected to reach HMRC by 31 May 2027, covering calendar year 2026.
Undeclared crypto gains now carry greater detection risk. Among all HMRC penalties 2026/27, the consequences for offshore concealment are the most severe, reaching up to 200%.
A voluntary disclosure facility is open for pre-April 2024 gains. Reporting crypto-asset service providers that breach CARF obligations face penalties of up to £300 per user.
Taxpayers should also note that capital losses from crypto disposals may be carried forward and offset against future gains. Any losses must be reported to HMRC within four years of the end of the tax year in which they arise.
Reasonable excuse and appeals
Not all HMRC penalties 2026/27 are final. HMRC may cancel or reduce a penalty where a taxpayer demonstrates a reasonable excuse.
Recognised grounds include bereavement, serious illness, an unexpected hospital stay and computer failure in limited circumstances. Evidence must be provided for each claim.
HMRC service issues, fire, flood, theft preventing record access and postal delays are also accepted. All claims require evidence and prompt action once the issue is resolved.
Taxpayers have a 30-day window to appeal any penalty. Appeals go first to HMRC and, if rejected, to the First-Tier Tribunal (Tax), which charges no fee.
How to avoid HMRC fines in 2026/27
The range of HMRC penalties 2026/27 means taxpayers at every level could face at least one charge. Acting before a deadline passes is far cheaper than dealing with fines afterwards.
Understanding how to avoid HMRC fines starts with knowing which deadlines apply. The list below covers the most important steps for the current tax year.
Steps to take now
- Check whether you fall within Making Tax Digital by reviewing your gross income on your 2024 to 2025 tax return against the £50,000 threshold.
- Set up MTD-compatible software and note your quarterly update deadlines if you are mandated or joining early.
- Review any undeclared income and consider a voluntary disclosure before HMRC contacts you.
- Set up a Time to Pay arrangement online before the 15-day penalty window opens if you anticipate difficulty paying.
- Keep records for at least 22 months after the tax year for individuals, or six years for businesses.
If you have received a P800 tax calculation letter or suspect your tax code may be wrong, checking your position now is worthwhile. Our guide explains how to verify whether a tax notice from HMRC is genuine.
Read the full guide: Is your P800 letter real? How to spot a fake tax notice.
Key Takeaways
- HMRC late payment interest stands at 7.75% per year, reflecting the base rate of 3.75% plus the widened 4% margin introduced in April 2025.
- The MTD points-based penalty system is live from April 2026, with a soft-landing year suspending quarterly update penalties for 2026 to 2027.
- Stepped late payment penalties of up to 6% at day 30, plus 10% per year from day 31, make delayed payment significantly more costly.
- Failure-to-notify penalties can reach 200% of unpaid tax for offshore matters, and HMRC can assess up to 20 years of back tax.
- Crypto investors face heightened scrutiny as CARF data sharing began on 1 January 2026; a voluntary disclosure facility remains open for pre-April 2024 gains.
