Note: HMRC are currently rolling out their new Making Tax Digital (MTD) system for income tax. For more information, check out our guide to MTD for sole traders.
If you’re a freelancer or sole trader using Self Assessment, knowing when things are due is pretty crucial – nobody wants surprise penalties from HMRC (they’re about as fun as they sound).
Luckily, Self Assessment deadlines are actually pretty straightforward once you’re across them. Let’s walk through all the key dates you need to keep on your radar.
Registration deadline
First things first: you’ll need to register for Self Assessment by 5 October after the end of the tax year you’re filing for. HMRC doesn’t set different registration dates for paper or online filers – the 5 October rule applies to everyone.
Self Assessment applies to the tax year that’s just been, not the one you’re currently in. So if you need to file a tax return for the 2024/25 tax year (which runs from 6 April 2024 to 5 April 2025), you’d need to register by 5 October 2025. Miss this date and HMRC may charge a penalty, which is never ideal.
Good news though: you only need to register once. After that first time, you’ll be able to sign in with your existing credentials for future Self Assessment tax returns.
Paper tax return deadline
If you’re old school and filing by post (fair play), your paper Self Assessment tax return needs to arrive at your local HMRC office by 31 October.
Paper returns are a bit more manual as you’ll need to calculate your tax yourself and fill in extra pages. According to HMRC, 97% of people file online these days, which is generally a lot easier. But if paper’s your thing, just make sure you post it early enough to arrive on time!
Online tax return deadline
For those filing online (most of us), your Self Assessment tax return is due by 31 January the year after the tax year you’re filing for.
So for the 2024/25 tax year, you’d file your online return by 31 January 2026. The online system is much friendlier – it automatically generates the sections you need to complete, and calculates your tax for you.
Which brings us to –
Tax payment deadline
Any tax you owe is also due on 31 January – the same date as your online tax return.
This covers your income tax, National Insurance contributions, and student loan repayments (if applicable). Make sure your payment clears by this date, because HMRC charges interest and penalties on late payments. Not fun for your bank balance!
To make things easier, you could complete your tax return well before the January deadline. That way you’ll know exactly what you owe ahead of time, and have breathing room to sort your final tax bill.
Payments on account deadlines
Now here’s where it gets slightly spicy.
If your tax bill is over £1,000, and you didn’t pay at least 80% of your income tax through other means (like a salaried job), you’ll need to make payments on account.
These are basically prepayments towards next year’s tax bill (you’ll still need to pay this year’s in full!), split into two instalments:
- First payment: 31 January (yes, on top of your current tax bill – we can’t stress this enough!)
- Second payment: 31 July
Each payment is usually 50% of the previous year’s income tax bill. HMRC will let you know if you need to make these payments when they calculate your tax.
Don’t fancy remembering all this?
Look, we get it – keeping track of multiple tax deadlines while running your business isn’t exactly thrilling. This is why Hnry exists.
For just 1% +VAT of your self-employed income (capped at £600 +VAT per year), we automatically set aside everything you owe to HMRC every time you get paid. This includes your:
- Income tax
- VAT (if applicable)
- National Insurance contributions
- Student loan repayments (if applicable)
We’ll also complete your Self Assessment tax return for you – it’s all part of the service. No deadlines to remember, no last-minute panic, no surprise bills.
Plus, we’re Making Tax Digital-compatible, so you’re future-proofed for HMRC’s upcoming changes to their tax filing system.
Join Hnry and never think about tax again.
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