Brits who earn over £1,000 from side hustles face important 14-day HMRC deadline

Are you thinking about creating a side hustle beyond your full-time job? It could end up costing you if you don't understand the HMRC rules that need to be followed by the next couple of weeks.

If there's one UK government body you don't want to mess up with, it's going to be the HM Revenue and Customs (HMRC) responsible for dolling out tax bills and National Insurance contributions for all people who earn money outside of employment PAYE processes.

However, there are dates and figures to be wary of, and if you don't follow the rules, you could be in hot water.

When it comes to HMRC and completing independent work, such as a hobby that pays, an Etsy shop, or anything that brings cash to your hand that isn't a non-taxable benefit, HMRC will want to know.

There's an important HMRC date (Getty Stock Images)

But there are a lot of rules and processes around this very thing, and namely, it only pertains to those who are making over one thousand pounds in additional cash per year.

So, if this sounds like you, here's a little explainer, so you're not accidentally missing an important part of logging your work (if you meet the criteria).

You need to file your tax return if you make over a grand a year (Getty Stock Images)

What are the HMRC rules?

If you're not too up to date on the Self-Assessment process, what it means is that if you work outside of employed work that pays and taxes you, you'll need to notify HMRC by 5 October and file a tax return by 31 January 2027 if you've made anywhere past £1000 within the financial year running from April 2025 to April 2026.

With so many ways the rules can be changed based on your income and circumstances, thankfully, HMRC’s free online checking tool on GOV.UK can help you figure out what category you fall under.

Because if you're wrong, you could face a penalty.

According to Myrtle Lloyd, HMRC’s Chief Customer Officer: "Anyone new to Self Assessment may not realise they need to register before they can submit their tax return. Registering is quicker and easier than ever. And if you register now, you’ll get your Unique Taxpayer Reference so you can start completing your return with plenty of time before the 31 January deadline."

For those who qualify for registration, they can register for tax via their Personal Tax Account which includes easier filing steps after recent streamlined changes made by HMRC.

This includes forms with pre-populated customer information, save and return functions with no loss of data, and more.

You'll need to register first (Getty Stock Images)

What else will you need?

Once registered, any and all who need to file tax will get a Unique Taxpayer Reference (UTR), and instead of waiting 15 days for the letter like previous self-employed people had to do, they can now enjoy the UTR being handed over within 72 hours before they can file their tax assessments.

However, while a lot of this pertains to people earning over a grand in a year, there is also an option to file and pay even if you earned below £1,000 but want to make voluntary Class 2 National Insurance Contributions to protect State Pension and benefit entitlement.

You'll also have to register if you have received any untaxed income over £2,500 in any capacity or have become the partner of a business.