Employed (PAYE)

Your First Self Assessment

For employed people with side income who have just found out they need to file.

7 lessons About 43 minutes By Laura Michelle Davis ✓ Reviewed by TaxFly Admin Figures for 2026/27
You have a job, and something on the side: eBay, a lodger, freelance work, dividends or savings interest. Somebody has told you that you might need to file a tax return. This course establishes whether you do, and walks you through it once, calmly.

By the end of this course you will be able to

  • Establish whether you actually need to file
  • Understand how side income is taxed alongside a salary
  • Know which allowances cover savings, dividends and trading
  • Complete a return that includes both employment and other income
  • Avoid the penalties that catch first-time filers

What you will cover

Module 1

Do you need to file?

Settling the question before you do anything else.

Most people who worry about Self Assessment do not need to file, and a smaller group who are not worried do. The rules are not intuitive, because they turn on the type of income rather than the amount, and because four separate allowances can each cover you.

This module settles the question. If the answer is no, you can stop reading and get on with your life.

  1. 1.1 Do you need to file at all? Your situation · 6 min · includes a calculator
  2. 1.2 The allowances that may cover you Lesson · 6 min · includes a calculator
Module 2

Side income alongside a salary

How the two interact, and why side income feels so heavily taxed.

Side income is taxed differently from your first pound of salary, and the difference surprises people. Your job has already consumed your personal allowance and often your basic rate band, so extra income starts higher up the scale.

These three lessons explain that arithmetic, cover savings and dividends, and deal with the question everyone with an eBay account now asks.

  1. 2.1 How side income is taxed on top of a salary Workshop · 6 min · includes a calculator
  2. 2.2 Savings interest and dividends Lesson · 6 min · includes a calculator
  3. 2.3 Selling online: when it becomes trading Story · 6 min · includes a calculator
Module 3

Getting it done

Registering, filing, and the penalties that catch first-timers.

The mechanics, once you know you must file. The form is far smaller than it looks for someone with a salary and one extra income source, and the penalty regime is harsher than most first-timers expect.

  1. 3.1 Registering and filing Workshop · 7 min · includes a calculator
  2. 3.2 The penalties that catch first-timers Checkpoint · 6 min · includes a calculator

Finish with the exam

10 questions covering the whole course. Score 80% or more and you get a certificate of completion. You can retake it as many times as you like.

The exam needs a free account, so we can save your result. The lessons themselves never do.

Go to the exam

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