The deadline for online Self-Assessment tax returns is 31 January, which feels comfortably far away for most people in the summer months.

The reality is that the tax year ended on 5 April, which means your 2025/26 return can be filed any time from 6 April 2026 onwards.

There is no advantage to leaving it until the last minute and several good reasons to get it done early.

You will know what you owe sooner

One of the biggest myths about Self-Assessment is that filing your return early means paying your tax bill early.

The payment deadline of 31 January remains exactly the same regardless of when you submit. What filing early actually gives you is time to budget and set money aside calmly, rather than scrambling for it in late January.

For anyone with a larger or more complex tax position, that breathing room can be extremely useful.

Refunds arrive faster

If you are due a refund, for example, because you overpaid tax through PAYE, made pension contributions or had Gift Aid donations to claim, the sooner you file, the sooner that money is back in your account.

Refunds claimed in April or May are often processed within a few weeks, whereas those claimed in late January can take considerably longer as HMRC works through the end-of-deadline rush.

You can plan for the rest of the year

Filing early gives you a clear picture of where you stand for the current tax year too. Knowing exactly what you owe for 2025/26 makes it far easier to plan ahead for:

  • Pension contributions to manage higher-rate tax exposure
  • ISA top-ups before the tax year end
  • Charitable giving with Gift Aid
  • Dividend and salary planning if you are a director

These are decisions best made in good time, not in the final weeks of the tax year.

You avoid the late-filing trap

HMRC’s penalty regime for late filing is stricter than many people realise. An immediate £100 fine applies the moment you miss the 31 January deadline, with daily penalties of £10 stacking up after three months. After six months, the penalties grow further.

Filing early removes that risk entirely and avoids the last-minute rush when both clients and their advisers are under maximum pressure.

Help is easier to get when you ask early

The best time to speak to your adviser is not in late January, it is now. Talking to a professional earlier in the year means more time for tailored advice and a more considered conversation about your tax position.

Speak to our team today about getting your Self-Assessment return filed early.