Self Assessment 2025/26: Key Dates and Making Tax Digital
Self Assessment 2025/26: Important Dates and Getting Ready for Tax Digital
If you're self-employed, a freelancer, or earn income outside your main job, you'll know that Self Assessment is a regular part of managing your finances. The 2025/26 tax year has one major deadline you need to keep in mind – 31 January 2027. But there's more to consider too: significant changes are coming in April 2027 with Making Tax Digital. Here's everything you need to know and when you need to act.
Do You Need to File?
Self Assessment applies if you:
- Are self-employed
- Have income from additional work or a second job
- Earn more than £1,000 from savings or investments
- Receive rental income from property
- Have other income with no tax deducted
If you're employed with only one job and the right tax is already removed from your salary, you generally won't need to file.
The Critical Deadline: 31 January 2027
This is the date your 2025/26 tax return must reach HMRC. Whether you file online or submit a paper form, this is your absolute deadline. File online at 23:59 on 31 January, or submit paper returns so they arrive by midnight the same day.
Filing even one day late results in a £100 penalty, with additional charges if the return remains outstanding. The penalties only increase from there, so meeting this deadline isn't optional.
Why Start Planning Now?
September is the ideal time to begin. Here's why:
- Records are still fresh – You're closer to the events of the tax year, making it easier to remember and find documents.
- Accountants are less busy – If you need professional help, you'll get better availability and faster service now than in November or December.
- You can identify gaps – Spotting missing records now gives you time to chase them up.
- You'll avoid stress – Starting early means no panicked last-minute scrambling in January.
Organize Your Records
Gather everything you need: invoices, receipts, bank statements, and documentation of expenses. Sort these by category – materials, equipment, travel, professional fees, home office, and so on.
HMRC doesn't require specific software for the 2025/26 year, but keeping organized digital copies of receipts is sensible practice. You only need the originals if HMRC asks.
Calculate Your Figures
Add up all income from every source during the tax year (6 April 2025 to 5 April 2026). Then list your business expenses, keeping records that show what each cost was for.
You can deduct legitimate business expenses: materials for your work, software subscriptions, professional memberships, travel for work, reasonable home office costs, and more. The key is that the expense must be directly for your business.
Don't estimate. Use your actual records and receipts. Being accurate now prevents problems later.
Understanding Making Tax Digital (April 2027)
This is a substantial change coming next year. From April 2027, HMRC is moving to a more digital system. Most self-employed people will need to:
- Use compatible software to track income and expenses throughout the year
- File quarterly updates instead of one annual return
- Keep records in digital format
For 2025/26, the old system still applies – you'll file one return by January 2027. But April 2027 marks the shift. If you're affected, you'll need to be ready with approved software and a new routine.
Will You Be Affected?
Most self-employed people with taxable income over roughly £12,570 will move to the new system. Exceptions include some very small businesses and specific circumstances.
Understanding whether this applies to you now means you can plan ahead. When April 2027 arrives, you won't be caught unprepared.
Get Clarity and Stay Organized
Managing Self Assessment successfully means knowing your key dates, staying organized, and understanding what's coming. Our Self Assessment 2025/26 guide sets out every deadline to 31 January 2027 and explains what Making Tax Digital means for you from April 2027, so you can stay ahead of both the current year's requirements and next year's changes.
Visit our shop to explore guides that help you manage Self Assessment with confidence.
Looking for ready-made templates and printables? Browse the shop.
Stay in the loop.
New templates and member-only offers, now and then. No spam. Unsubscribe in one click.