Find out if HMRC is expecting a tax return from you this year.
Self Assessment –
ace it with confidence
Find out everything you need to know to feel confident about Self Assessment, including key deadlines, who needs to file and how to complete your tax return.
How FreeAgent can helpKey dates for your diary
- Tax year to file for:
- 6th April 2021 - 5th April 2022
- Online tax return deadline:
- Midnight, 31st January 2023
- Final payment of tax due:
- Midnight, 31st January 2023
Breeze through Self Assessment with our helpful guides
Not sure where to start with your tax return? Browse through our topics and guides below to find the information you’re looking for.
Before the Self Assessment deadline
Our guide to the key Self Assessment dates throughout the year should help you avoid any nasty surprises.

Find out how and when to register for Self Assessment, and how the registration process might vary depending on your circumstances.

A breakdown of some of the key terms you’ll come across as you complete your Self Assessment tax return.
Here’s how you can foster a winning relationship with your accountant during Self Assessment season.

A list of all the things that you’ll need to have to hand in order to complete your tax return.
Find out which sections of the tax return you’ll need to complete and what information you’ll need to provide.
Find out what income you need to pay tax on - as well as the income you don’t!
Follow these useful tips to avoid the most common mistakes that people make in the rush to file before the deadline.
Learn more about the different ways you can pay your tax bill and how long it will take for your payment to reach HMRC.

Payments on account often catch business owners out. Here’s everything you need to know.
After the deadline

It’s going to be OK! If 31st January has been and gone, follow the tips in this guide to help minimise the impact of missing the deadline.
Made a mistake on your tax return? Here’s how to fix it.
Find out what HMRC might accept as a ‘reasonable excuse’ for missing the Self Assessment deadline.
The latest Self Assessment articles from our blog
Read more about Self Assessment on our blog.

Here are the steps you can take to appeal your Self Assessment penalty if you have a reasonable excuse.

Six ways to pay a Self Assessment penalty and avoid further charges.

The 31st January deadline for filing your Self Assessment tax return for the 2021/22 tax year is fast approaching. Fortunately, there are a few easy ways to file your tax return.
Get your Self Assessment checklist
Download your all-in-one guide to completing each step of your Self Assessment tax return.
Self Assessment videos
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Complete your Self Assessment tax return with confidence
If you're a sole trader or a limited company director, FreeAgent works away in the background to calculate your Self Assessment liability and prepare your tax return.
Get Self Assessment tax-confident Already a FreeAgent customer?
Our Knowledge Base has lots of helpful information about filing your Self Assessment tax return using FreeAgent.