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Guide
Do you have to file a Self Assessment tax return? Find out if HMRC is expecting a tax return from you this year.
Soar through Self Assessment
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. Learn more about how FreeAgent can help.
Key dates for your diary
- Tax year to file for:
- 6th April 2023 - 5th April 2024
- Online tax return deadline:
- Midnight, 31st January 2025
- Final payment of tax due:
- Midnight, 31st January 2025
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
Guide
Self Assessment deadlines: key dates you need to know Our guide to the key Self Assessment dates throughout the year should help you avoid any nasty surprises.
Guide
How to register for Self Assessment Find out how and when to register for Self Assessment, and how the registration process might vary depending on your circumstances.
Guide
Payments on account: everything you need to know Payments on account often catch business owners out. Here’s everything you need to know.
Guide
Everything you need to fill out your Self Assessment tax return A list of all the things that you’ll need to have to hand in order to complete your tax return.
Guide
Common tax return mistakes to avoid Follow these useful tips to avoid the most common mistakes that people make in the rush to file before the deadline.
Guide
How to complete your Self Assessment tax return Find out which sections of the tax return you’ll need to complete and what information you’ll need to provide.
Guide
How to calculate your business income for Self Assessment Find out what income you need to pay tax on - as well as the income you don’t!
Guide
How to pay your Self Assessment tax bill Learn more about the different ways you can pay your tax bill and how long it will take for your payment to reach HMRC.
Guide
Working with your accountant during Self Assessment season Here’s how you can foster a winning relationship with your accountant during Self Assessment season.
After the deadline
Guide
Missed the Self Assessment deadline? Here’s why you shouldn’t panic 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.
Guide
How to amend your tax return after you've filed it Made a mistake on your tax return? Here’s how to fix it.
The latest Self Assessment articles from our blog
Read more about Self Assessment on our blog.
14 April 2025
Self Assessment filing for 2024/25 is live in FreeAgent Get ahead of the game and file your tax return early.
4 February 2025
Late filing penalty reprieve for some taxpayers affected by basis period reform HMRC is waiving late payment penalties for some business owners - find out if you’re affected.
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Downloadable guide
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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, limited company director or unincorporated landlord, FreeAgent works away in the background to calculate your Self Assessment liability and prepare your tax return.
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Our Knowledge Base has lots of helpful information about filing your Self Assessment tax return using FreeAgent.
