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UK HMRC deadlines for sole traders

Every deadline HMRC expects a UK sole trader to keep — Self Assessment, Payments on Account, MTD for Income Tax, CIS monthly returns — in one plain-English list. Dates for the next twelve months, with the applies-to audience and the penalty if you miss it.

Next up · 17 days away

CIS300 return due

Saturday 19 September 2026 · CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).

File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.

The next 12 months

What’s coming and when

September 2026

  • 19 Sep

    Saturday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

October 2026

  • 5 Oct

    Monday

    Register for Self Assessment

    Registration
    Applies to
    New sole traders — first year self-employed in 2025–26
    What to do
    Register at gov.uk/register-for-self-assessment.
    Penalty if missed
    Failure-to-notify penalty (based on unpaid tax) if you register after this date.

  • 19 Oct

    Monday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

  • 31 Oct

    Saturday

    Self Assessment paper return

    Self Assessment
    Applies to
    Anyone filing their Self Assessment on paper.
    What to do
    Most tradespeople file online — you get an extra three months. Only paper is due 31 October.
    Penalty if missed
    £100 immediate penalty. Rises to +£10/day (up to £900) after 3 months, then 5% of tax due or £300 at 6 and 12 months.

November 2026

  • 7 Nov

    Saturday

    MTD Q2 deadline

    MTD for Income Tax
    Applies to
    MTD ITSA in-scope: qualifying income >£50k (2026/27), >£30k (2027/28), >£20k (2028/29).
    What to do
    Submit the quarter’s income + expenses via MTD-compatible software.
    Penalty if missed
    Points-based: one point per missed submission. Four points across four quarters = £200 penalty, plus £200 for each subsequent miss.

  • 19 Nov

    Thursday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

December 2026

  • 19 Dec

    Saturday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

January 2027

  • 19 Jan

    Tuesday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

  • 31 Jan

    Sunday

    MTD Final Declaration

    MTD for Income Tax
    Applies to
    MTD ITSA in-scope filers for 2025–26 (replaces Self Assessment).
    What to do
    Submit via MTD software. All four quarters must be filed first — this ties the year together.
    Penalty if missed
    Same penalty tier as Self Assessment: £100 immediate, then daily and percentage escalators.

  • 31 Jan

    Sunday

    1st Payment on Account

    Payments on Account
    Applies to
    Prior-year tax > £1,000. Advance for tax year 2026–27.
    What to do
    Half of last year’s tax bill, paid alongside your Self Assessment balancing payment.
    Penalty if missed
    Interest accrues from the day after. HMRC rate is 8.5% (Bank of England base + 2.5%) as of July 2026.

  • 31 Jan

    Sunday

    Self Assessment online return + tax payment

    Self Assessment
    Applies to
    All Self Assessment filers for 2025–26 (not in MTD).
    What to do
    File online at gov.uk and pay any balancing tax owed for the year that ended 5 April.
    Penalty if missed
    £100 for late return + 5% of unpaid tax at 30 days, another 5% at 6 months and 12 months, plus interest.

February 2027

  • 7 Feb

    Sunday

    MTD Q3 deadline

    MTD for Income Tax
    Applies to
    MTD ITSA in-scope: qualifying income >£50k (2026/27), >£30k (2027/28), >£20k (2028/29).
    What to do
    Submit the quarter’s income + expenses via MTD-compatible software.
    Penalty if missed
    Points-based: one point per missed submission. Four points across four quarters = £200 penalty, plus £200 for each subsequent miss.

  • 19 Feb

    Friday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

March 2027

  • 19 Mar

    Friday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

April 2027

  • 19 Apr

    Monday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

May 2027

  • 7 May

    Friday

    MTD Q4 deadline

    MTD for Income Tax
    Applies to
    MTD ITSA in-scope: qualifying income >£50k (2026/27), >£30k (2027/28), >£20k (2028/29).
    What to do
    Submit the quarter’s income + expenses via MTD-compatible software.
    Penalty if missed
    Points-based: one point per missed submission. Four points across four quarters = £200 penalty, plus £200 for each subsequent miss.

  • 19 May

    Wednesday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

June 2027

  • 19 Jun

    Saturday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

July 2027

  • 19 Jul

    Monday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

  • 31 Jul

    Saturday

    2nd Payment on Account

    Payments on Account
    Applies to
    Prior-year tax > £1,000. Advance for tax year 2026–27.
    What to do
    The second half of last year’s tax bill. Reduce it via HMRC if you know your income has dropped.
    Penalty if missed
    Interest accrues from the day after. HMRC rate is 8.5% (Bank of England base + 2.5%) as of July 2026.

August 2027

  • 7 Aug

    Saturday

    MTD Q1 deadline

    MTD for Income Tax
    Applies to
    MTD ITSA in-scope: qualifying income >£50k (2026/27), >£30k (2027/28), >£20k (2028/29).
    What to do
    Submit the quarter’s income + expenses via MTD-compatible software.
    Penalty if missed
    Points-based: one point per missed submission. Four points across four quarters = £200 penalty, plus £200 for each subsequent miss.

  • 19 Aug

    Thursday

    CIS300 return due

    CIS
    Applies to
    CIS contractors paying subcontractors. Filed monthly (per tax month, 6th–5th).
    What to do
    File the CIS300 for the tax month ending on the 5th of the previous month. Nil returns still required.
    Penalty if missed
    £100 immediate + £200 at 2 months. £300 or 5% of deductions (higher) at 6 and 12 months.

Where’s VAT?

VAT return deadlines depend on your HMRC-assigned stagger (1, 2 or 3) — which quarters HMRC has you filing on. We can’t list them canonically here.

The rule is: one calendar month + 7 days after your quarter end. If your quarter ended 30 June, your return is due 7 August.

Check your dates at gov.uk

Are you in MTD scope?

MTD for Income Tax phases in by qualifying income — your gross self-employment + property income from the previous full tax year:

  • 2026/27: in scope if 2024/25 income > £50,000
  • 2027/28: in scope if 2025/26 income > £30,000
  • 2028/29: in scope if 2026/27 income > £20,000
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