The SA103 is a form that you need to attach to your SA100 main Self Assessment form if you need to pay tax on income from self-employment.
You’re self-employed (also called a “sole trader”) if:
There are two versions of the SA103:
You can download the SA103 quickly and easily on HMRC’s website. Similar to the main SA100 form, you only need to print it and mail it if you don’t do your file return online.
Of course! We advise that you start a comprehensive spreadsheet to keep track of your taxable income and relevant expenses throughout the year in order to make your tax return more straightforward. This can be done on an Excel spreadsheet or Google sheet to keep things simple! Contact our team for more advice today!
If you are a self-employed contractor, remember to file your Self Assessment by 31st January the year after the tax year you’re paying for. For example, if you’re paying your 2023/2024 tax return, this should be paid by 31st January 2025. To learn more about the SA100 Self Assessment tax return, visit our dedicated SA100 glossary page.