Start here · 2 pages
Do I need to tell HMRC?
A few yes/no questions, the money limits, how to register for Self Assessment, and whether you count as self-employed.
For: anyone not sure where they stand.
Ask Martin: tax return help
Do you need to tell HMRC?
Earning a bit on the side, getting rent, or working for yourself? These free handouts explain, in plain English, whether you need to do a tax return, what to do and by when, and where to get help if you need it.
Please note: this is general information, not tax advice.
Everyone's situation is different. If you're not sure what applies to you, check GOV.UK or talk to a qualified professional.
Start with Sheet AA few yes/no questions tell you which other sheets to read. Most people need only one or two.
Plain EnglishShort sentences and everyday words, with a "Words explained" box on every sheet.
Clickable sourcesEvery sheet lists its GOV.UK and other trusted links at the end.
The six help sheets
Download, print or share.
Each sheet is a free PDF for the 2025/26 tax year (6 April 2025 to 5 April 2026), with clickable links to GOV.UK and other trusted sources.
3 pages
Side gigs and selling online
Selling on Etsy, eBay or Vinted, crafts, odd jobs and gig work. The £1,000 trading allowance, what selling sites report to HMRC, and a section for under-18s.
For: anyone earning a bit on the side.
3 pages
Money from property
Lodgers, holiday lets and Airbnb, and letting a house or flat. The Rent a Room scheme, what costs you can claim, and changes on the way.
For: anyone receiving rent.
3 pages
Sole traders and small businesses
How your tax bill is worked out, what you can claim, simplified expenses, payments on account and setting money aside.
For: anyone whose main living comes from working for themselves.
3 pages
As your business grows
Making Tax Digital, VAT, and whether a limited company would suit you. For the step-by-step version, see the business guides.
For: sole traders and landlords whose income is growing.
3 pages
Getting the right help
Whether you need help at all, who does what, how to check someone's qualifications, and warning signs to look out for.
For: anyone thinking about paying for help.
Quick guide
Which sheet do I need?
More than one fits? Read each of them. Many people have a job and a side gig, or a business and some rent.
| Read | If you... |
|---|---|
| Sheet A | aren't sure whether you need to tell HMRC at all |
| Sheet B | sell things online, make crafts, or do odd jobs or gig work alongside a job |
| Sheet C | get rent from a lodger, a holiday let, Airbnb, or a house or flat |
| Sheet D | work for yourself as your main living |
| Sheets E and F | are already filing tax returns, and your income is growing |
| Sheet F | are thinking about paying a bookkeeper, accountant or adviser |
Key dates for 2025/26 tax returns
The big one is 31 January 2027.
That's the last day to send your tax return online and pay what you owe.
| Date | What's due |
|---|---|
| 5 October 2026 | Last day to register if this is your first tax return. Missed it? Register now. You'll usually avoid a fine if you send your return and pay by 31 January. |
| 31 October 2026 | Last day for paper tax returns. |
| 31 January 2027 | Online tax return, any tax you owe, and your first payment on account if one is due. |
| 31 July 2027 | Second payment on account, if one is due. |
What to do next, step by step: Tax Ready takes you from "do I need a return?" to "filed and paid", with a 2-minute check and a personal action plan.
A late tax return means an automatic £100 fine, even if you owe no tax. Check the latest dates on GOV.UK.
Free help and staying safe
You don't have to pay anyone.
Many people with one simple income do their tax return themselves, for free, on GOV.UK.
Do it yourself, freeRegister for Self Assessment and send your return online on GOV.UK. Never pay a website to register you.
Check if you need a returnUse HMRC's free online checker.
On a low income?TaxAid is a charity that gives free, private tax help to people who can't afford an adviser.
Beware of scamsHMRC never texts or emails you about a refund or asks for your bank details. Never share your HMRC login with anyone.
Want someone to do it for you? Sheet F explains how to choose a bookkeeper or accountant, and what to check first. MRS Bookkeeping is one option: it is supervised by HMRC for anti-money-laundering purposes and is a registered HMRC agent. Please check us in the same way as anyone else.
About these handouts
Written for the questions that keep coming up.
I'm Martin Schmalenbach of MRS Bookkeeping in Dolton, Devon. I wrote these sheets for the free "Ask Martin" tax return drop-in clinics in October 2026, because the same questions kept coming up: do I need to tell HMRC, what do I have to do, and when?
Every figure is checked against GOV.UK or another trusted source, and each sheet lists its sources at the end. The sheets use the rules for England, Wales and Northern Ireland. Scotland's Income Tax rates are different.
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