Filing your 2025-26 self-assessment tax return

The 2025–26 tax year ended on 5 April 2026, and attention now turns to filing your self-assessment tax return. While many leave this until the last minute, there are advantages to filing early.

There are two ways to file your return. You can submit a paper return, which must be filed by 31 October 2026, or file online, with a deadline of 31 January 2027. The 31 January deadline is also when any tax due for 2025–26 must be paid, along with the first payment on account for 2026–27.

Although the deadline may seem distant, preparing your return early can make a significant difference. Filing early does not accelerate the payment date, but it does give you certainty over how much tax you owe. This allows time to budget and set funds aside, avoiding pressure in January.

There are other benefits too. If you are due a refund, submitting early means you receive it sooner. It also gives more time to gather missing information, resolve queries, and avoid the last-minute rush when systems are busy and deadlines are tight.

In short, early preparation puts you in more control, whether that means planning for a future tax bill or importantly securing a repayment without delay.

Source:HM Revenue & Customs | 19-04-2026
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Aitch
Aitch is the visionary founder and CEO of CIGMA Accounting Ltd, a boutique accounting and tax advisory firm with offices in Wimbledon and Farringdon, London. With over a decade of experience, Aitch has built a reputation for strategic tax planning, complex HMRC compliance resolution, and innovative AI-powered accounting workflows that help SMEs, landlords, and high-net-worth clients streamline their finances. His expertise spans corporation tax, inheritance tax planning, R&D tax credit claims, capital allowances, and international tax matters, making him a trusted advisor for clients seeking to minimise tax liabilities while staying fully compliant. Aitch is passionate about bridging traditional accounting principles with cutting-edge digital solutions, allowing businesses to operate efficiently and future-proof their financial systems. Through CIGMA, he aims to make accounting smarter, faster, and more human-centric - empowering clients to focus on growth while staying ahead of regulatory changes.