Self-employed tax dates for 2026/27 and what to do before each one

Running your own business can mean freedom, flexibility, and a diary full of tax dates that refuse to move. The 2026/27 tax year brings the usual Self Assessment deadlines, plus a big shift into digital reporting for many self-employed people.

Now that we’re up and running in the tax year, we wanted to confirm the key dates, explain what each one means, and set out what to do ahead of time so nothing sneaks up on you.

If you’re not doing this already, we’d suggest:

• Checking your tax code if you also have PAYE income.
• If your self-employment or property income exceeded £50,000, you now fall into Making Tax Digital for Income Tax Self Assessment (MTD ITSA) and so need to be keeping digital records using compatible software.
• Putting a system in place for tracking income and expenses weekly rather than in one painful January rush.

If your income sits below £50,000, you still follow traditional Self Assessment for now, but the rules change again in April 2027 when the threshold drops to £30,000.

31 July 2026 – Second payment on account due

If your last tax bill exceeded £1,000, HMRC usually asks for payments on account. This July date covers the second instalment for the 2025/26 tax year.

What to do beforehand

• Review last year’s profits and confirm the payment amount in your HMRC account.
• If income has dropped significantly, you can apply to reduce payments on account, though accuracy matters because underpaying leads to interest.
• Set aside funds early. July often clashes with quieter trading periods or summer holidays, which catches people out.

7 August 2026 – First MTD quarterly update (for those in scope)

For self-employed people mandated into MTD for Income Tax from April 2026, the first quarterly update covers 6 April to 5 July 2026, and is due by 7 August 2026.

What to do beforehand:

• Make sure your software is fully set up and connected to HMRC.
• Keep digital records up to date rather than uploading everything at the last minute.
• Review the figures before submission. Quarterly updates are summaries, not final tax calculations, but accuracy still helps with cashflow planning.

HMRC has confirmed there are no penalties for late quarterly submissions during the 2026/27 transition year, but that breathing space will not last forever.

5 October 2026 – Register for Self Assessment (if you are new)

Anyone who became self-employed during the 2025/26 tax year and has not filed before must register for Self Assessment by 5 October 2026.

What to do beforehand

• Register online and wait for your Unique Taxpayer Reference (UTR).
• Do not leave this late. Without a UTR, you cannot submit a return.
• Even if no tax is due, registration is still required if income exceeded £1,000.

31 October 2026 – Paper tax return deadline

If you’re still filing on paper this is the deadline for submitting a paper Self Assessment return for 2025/26.

What to do beforehand

• Gather bank statements, invoices, expense receipts, and mileage logs.
• Post the return with plenty of time to spare.
• Consider switching to online filing, which gives you three extra months and instant submission confirmation.

30 December 2026 – PAYE collection option closes

If you file online and owe less than £3,000, HMRC can collect the tax through your PAYE code, but only if the return is submitted by 30 December 2026.

What to do beforehand

• File early if spreading payments through PAYE helps cashflow.
• Double‑check eligibility if you have multiple income sources.

31 January 2027 – The big one

This date does three things at once:

• Deadline to submit your online Self Assessment return for 2025/26
• Deadline to pay any remaining tax for 2025/26
• Deadline to pay the first payment on account for 2026/27

Miss it, and automatic penalties start immediately.

What to do beforehand

• File well before January so the tax bill holds no surprises.
• Check that payments on account are correct.
• If cashflow feels tight, explore Time to Pay options early rather than after the deadline.

A final word on planning ahead

The 2026/27 tax year that ends on 5^th April 2027 rewards organisation. Digital record‑keeping, earlier visibility of tax liabilities, and spreading the workload across the year all make a noticeable difference. The move to Making Tax Digital may feel like extra admin, but for many businesses it removes the January panic entirely once routines settle.

At Howden, we’re here to support you with your insurance needs whatever business you’re in, while you focus on what you do best; getting the job done.

Sources: Tax Radar, The Tax Guide, GOV.UK, Making Tax Digital