I am late for Self-Assessment Tax Returns. What I should do now?

Every year, thousands of UK taxpayers miss the self-assessment tax return deadline. While it may feel like a minor oversight, HMRC takes late filing seriously and can issue penalties even if no tax is due or your tax has already been paid. Understanding the consequences — and acting proactively — is crucial.

Penalties for Late Submission

Missing the filing deadline can trigger several consequences:

• Initial fixed penalty: £100 immediately after the deadline.
• Daily penalties: Additional fines accrue if the return remains unfiled after three months.
• Ongoing enforcement reforms: HMRC has already introduced a penalty-points system for VAT and other tax regimes, signalling a broader move toward stricter enforcement for repeated non-compliance.
• Interest on unpaid tax: Interest starts accruing from 1 February onwards, even if you file late.

Filing your tax return as soon as possible remains the top priority, even if you cannot pay the full tax immediately. In some cases, HMRC may allow a Time to Pay arrangement, but late filing penalties can still apply.

Why Taxpayers Fall Behind

Late submission for self-assessment tax return is not uncommon. In fact our office at Elaga Accountancy have received re quest for assistance for help every year, including single year or mutliple years overdue, some even after official windows of all overdue submission. Some of the common reasons for late filing include:

• Missing the October or January deadlines.
• Having complex income sources, such as overseas income or multiple properties.
• Uncertainty about whether a tax return is required.

Even small oversights can trigger penalties, and HMRC has dedicated compliance staff to follow up on overdue returns.

Beyond Standard Penalties – Serious Overdue Cases

Late filing is not always just about the £100 fine. HMRC treats deliberate or prolonged non-filing seriously. Cases where taxpayers have avoided filing for multiple years — even where the taxpayer claims they were unaware of the obligation — may be treated as deliberate non-compliance.

Possible consequences include:

• Higher penalties covering multiple years of unfiled returns.
• Backdated interest and formal compliance checks.
• In extreme situations, referral for criminal investigation.

There have been cases where individuals failed to realise they needed to submit tax returns for over 20 years. Once HMRC identified the issue, the matter was treated as serious, with penalties calculated on the basis of deliberate behaviour rather than simple oversight.

HMRC’s Increased Enforcement Power (Announced 2025)

HMRC is no longer under-resourced. In June 2025, the UK government announced a £1.7 billion funding boost over four years to significantly strengthen HMRC’s compliance and enforcement capability. This was described as the most ambitious package ever introduced to close the UK’s tax gap, currently estimated at £46.8 billion.

Under this plan, HMRC will recruit:

• 5,500 additional compliance officers
• 2,400 additional debt-management staff

The funding is targeted at identifying late filers, deliberate non-filing, understated income, offshore income, and unpaid tax debts, supported by enhanced data analytics, AI tools, and HMRC’s Connect system.

The government estimates this investment will generate an additional £7.5 billion in recovered tax by 2029/30. In practical terms, HMRC now has both the financial incentive and the manpower to actively pursue overdue and incorrect tax filings.

For taxpayers, this means the risk of “slipping under the radar” is lower than ever. Long-term non-filing, repeated late submission, or undeclared income is increasingly likely to be detected and followed up — often with backdated penalties and interest.

All Self‑Assessment Tax‑Return Submission Windows Are Closed – What Should You Do Now?

If you have missed filing deadlines:

1. Do not panic — filing late is always better than not filing at all.
2. Gather your records — bank statements, investment income, property income, and expenses.
3. File as soon as possible — this reduces further penalties and interest.
4. Seek professional help — especially if your situation involves overseas income, self-employment, or multiple income sources.

Voluntarily addressing overdue returns is almost always better than waiting for HMRC to contact you first.

Seek Professional Help  

The submission windows for both submission in paper format and electronically have been closed officially for tax payers. HMRC guideline hasn't mentioned these channels can be reopened for overdue submission to tax payers. So somehow you will need to contact HMRC office. Anyhow you will be contacted through their overdue notice in very short period. Penalty may be unavoidable. With official submission windows closed you may not want further trouble and submit correctly. Sometimes some tax payers even have tax returns of more than one or two years overdue, then every official is closed. In this occasion like this you want to seek professional help. Our team at Elaga Accountancy specialises in UK self-assessment tax return filing, handling both straightforward and complex cases. We can:

• Review and organise your records.
• Submit overdue or current tax returns accurately and promptly.
• Minimise penalties and interest where possible.
• Provide clear guidance so you remain compliant going forward.

Even if your tax return is overdue, don’t wait until HMRC discovers it. Contact us today — we will do our best to help you file correctly and safely.

***Contact us to learn more.

#LateSelfAssessment #LateTaxReturn #SelfAssessmentTaxReturn #HMRCpenalties #SelfAssessment #HMRC #TaxPenalties #OverdueTax #UKTax #TaxFiling #Accountancy #TaxAdvice #TimeToPay #OverdueTaxReturn #UKTaxFiling #HMRCCompliance #TaxReturnLate #TimeToPay #UKAccountant