Self Assessment quick compliance check

Use this checklist to confirm you are on track with your Self Assessment obligations for the current tax year.

Key deadlines

Filing and payment deadlines

Confirm you know when your return is due and when payment must reach HMRC.

Paper return deadline: 31 October 2026 (11:59pm)
Online return deadline: 31 January 2027 (11:59pm)
Earliest submission date: 6 April 2026
Pay through tax code deadline: 30 December 2026 (to collect via PAYE)
Amendment window: 12 months from the Self Assessment deadline

Paper returns must be received by HMRC, not just posted. Online filing is recommended as it provides immediate confirmation.

Payment deadlines and payments on account

Check whether you need to make payments on account in addition to your balancing payment.

Main payment deadline: 31 January following the tax year end
First payment on account: 31 January (during tax year)
Second payment on account: 31 July (after tax year ends)
Balancing payment: 31 January (if actual liability exceeds payments on account)

Filing your return

Confirm your return is filed or on track. Filing early gives you more time to arrange payment.

File your Self Assessment tax return

Deadlines, supplementary pages, and step-by-step filing process.

Payment

Confirm your payment method and allow enough processing time before the deadline.

Pay your Self Assessment tax bill

Payment methods, processing times, and options if you cannot pay in full.

Penalty risks

Check that you are not at risk of penalties for late filing or late payment.

Avoid Self Assessment penalties

Penalty escalation, interest rates, and how to appeal if penalised.

Late filing penalties

Penalties start at a fixed charge and escalate the longer you delay.

1 day late: £100 fixed penalty (applies even if no tax owed)
3 months late: £10 per day (up to 90 days = £900 maximum)
6 months late: 5% of tax owed or £300, whichever is higher
12 months late: Additional 5% of tax owed or £300, whichever is higher
Maximum penalty: Up to 100% of tax owed in serious cases

Penalties are cumulative. Filing 12 months late can result in £100 + £900 + two 5% penalties. Partnership returns incur penalties for all partners if late.

Making Tax Digital readiness

Check whether you are affected by the upcoming MTD for Income Tax requirements.

Prepare for Making Tax Digital

Phased rollout thresholds, software requirements, and quarterly deadlines.

MTD for Income Tax thresholds

MTD for Income Tax is being phased in from April 2026 based on income thresholds.

Phase 1: From 6 April 2026: Qualifying income over £50,000 (approx. 780,000 individuals)
Phase 2: From 6 April 2027: Qualifying income over £30,000 (additional 970,000 individuals)
Phase 3: From 6 April 2028: Qualifying income over £20,000
Qualifying income definition: Combined self-employment and property income (excludes employment, pension, savings, dividends)

Requirements: Keep digital records, use MTD-compatible software, submit quarterly updates, submit final declaration by 31 January.

Find MTD-compatible software (opens in a new tab)

Self Assessment quick compliance check