TaxWiz Logo
Tax Year 2026/27 Ready

Self Assessment,
Translated.

No Latin. No £200/hr accountant fees. Just the roadmap you need to stay on the right side of the taxman.

Start The Guide Tax Calculator
The 2026/27 Stack
Over £125,14045% Tax Zone
£50,271 – £125,14040% Tax Zone
£12,571 – £50,27020% Tax Zone
Up to £12,570£0 Income Tax

*Assumes standard Personal Allowance

Do You Actually Need to Register?

The biggest myth in UK tax is that you must register the second you earn a penny. This is false. Unless your annual gross income (total sales) is over £1,000, HMRC usually doesn't require a return.

In Plain English

What is "The Trading Allowance"?

This is your 'free tax pass'. If you earn less than £1,000 from side hustles or freelance work in a single tax year, you usually don't need to tell HMRC anything.

The TaxWiz Guarantee

Our engine verifies every fact against the latest HM Revenue & Customs (HMRC) bulletins. No outdated rules. Just current, actionable tax intelligence.

  • Verified for 2026/27
  • HMRC Manual Referenced
  • No Professional Jargon

The 4-Step Roadmap

It feels like a mountain, but filing your first return is just a sequence of four events.

01

Register for UTR

Tell HMRC you exist. They send a 10-digit code in the post.

Deadline: 5 October
02

Log Expenses

Software or spreadsheets. Keep every receipt for tools and travel.

Ongoing
03

File Returns

Log into the portal and enter your total income and costs.

Deadline: 31 Jan
04

Pay the Taxman

Bank transfer the total bill to avoid penalties.

Deadline: 31 Jan

Essential Reading

Everything you need to successfully navigate the HMRC gauntlet, ordered logically from start to finish.

Browse the full archive
1

What is Self Assessment?

The plain-English absolute beginner's guide to how UK filing works.

2

What is a UTR Number?

Your 10-digit tax DNA. Learn where to find it and why you need it.

3

Do I Actually Need to Register?

The definitive checklist to know if HMRC cares about your income.

4

The £1,000 Trading Allowance

Learn how to earn side income tax-free without even telling HMRC.

5

What Counts as an Allowable Expense?

Can you write off your phone bill? We break down exactly what is legal.

6

What Happens If You File Late?

Missed the Jan 31st deadline? Learn the costs and how to stop the fines.

Self Assessment FAQ

Need a quick answer?

Yes. If you make less than £1,000, you don't even need to register. If you make more, you can choose to deduct £1,000 from your income instead of your actual expenses to simplify your math.
No. This is your 'Personal Allowance'. Most UK residents don't pay a penny of Income Tax on the first £12,570 they earn across all their jobs combined.
HMRC issues an automatic £100 penalty the second you are late. This increases every 3 months. It’s always better to file on time, even if you can't pay the bill immediately.