1 Million Could Miss Today's HMRC Deadline, Even If They Pay Tax

Tax Queen

Tax Expert @ Pie

3 min read

What You Need to Know

Around 1,000,000 people in the UK could miss today's HMRC deadline, including many who already pay tax through their job. If you earned money outside your employment between 6 April 2025 and 5 April 2026, from freelancing, a side hustle, renting out property or a business partnership, you may need to register for Self Assessment by 5 October 2026. Registering is free and takes place online. Your tax return and any tax you owe aren't due until 31 January 2027.

Why Paying Tax Through Your Job Isn't Enough

Everyone in the UK gets a Personal Allowance. This is the amount you can earn each year before paying Income Tax, and it's currently £12,570. If you're employed, your employer handles the rest through PAYE (Pay As You Earn). Tax comes off your wages before you're paid, usually at 20% on earnings between £12,571 and £50,270 (Scotland has different bands).

That system only covers the money you earn from your job. HMRC has no record of what you make on the side. Unless you tell them, they don't know it exists, and no tax has been taken off it.

It doesn't matter whether you work full time, part time or only now and then. If you need to send a tax return for the 2025/26 tax year and you've never sent one before, you must tell HMRC by today. The same applies if you registered before but didn't need to send a return for 2024/25.

Who Needs to Register

You'll usually need to register if, in the 2025/26 tax year, you:

Earned more than £1,000 from self-employment, freelancing or a side hustle (before expenses)
Received more than £1,000 in rental income (you may need to register)
Were a partner in a business partnership
Had other income that wasn't taxed at source, such as income from abroad

The £1,000 figure comes from the trading allowance and the property allowance. These are tax-free amounts for small earnings. Despite what some reports say, you don't need to contact HMRC if you don't need to send a return. If you're unsure, use HMRC's check if you need to send a tax return tool.

If this is your first time dealing with Self Assessment, Pie Tax is a self assessment tax app built for people with a job and income on the side, as well as full-time sole traders and landlords.

What to Do Before the End of Today

Register Online With HMRC

You register on GOV.UK using a Government Gateway account. If you don't have one, you can set it up as part of the process. HMRC will then post you a Unique Taxpayer Reference (UTR). This is a 10-digit number that identifies you for tax. Waiting times vary, so you can use HMRC's online tool to check when to expect it.

Using an Accountant? You're Still Responsible

HMRC is clear on this. If you ask someone else, such as an accountant or adviser, to register you, it's still your job to make sure they do it. If they miss the deadline and you didn't check, the penalty can still land on you. Get confirmation that it's been done.

Then Get Ready for 31 January

Registering only tells HMRC you exist. It doesn't file anything. You still have to submit your tax return, listing your income and expenses, and pay any tax you owe by 31 January 2027. See how Pie Tax works to understand how the app tracks your figures and builds your return as you go.

Missed the Deadline? Here's What Actually Happens

You may have read that missing today's deadline means an instant £100 fine, rising to £900. That's not right. Those figures are for filing your tax return late, which is a different deadline.

Registering Late

If you register after 5 October and don't pay your full tax bill by 31 January 2027, you may get what HMRC calls a "failure to notify" penalty. It's based on the amount of tax still unpaid. If you register late but still file and pay in full by 31 January, you usually won't get a penalty.

Some reports also claim these penalties only apply to deliberate failures. That's not true either. The penalty can reach 30%of the unpaid tax even when it was an honest mistake, 70% if it was deliberate and 100% if someone deliberately hid it. If you tell HMRC yourself before they contact you, and do it within 12 months, a non-deliberate penalty can be cut to nothing. If you had a reasonable excuse, such as serious illness, you can appeal against the penalty.

Filing Your Return Late

Miss the 31 January filing deadline and the penalties add up:

£100 straight away, even if you owe no tax
After 3 months, £10 a day for up to 90 days (a maximum of £900)
After 6 months, 5% of the tax due or £300, whichever is higher
After 12 months, another 5% or £300, whichever is higher

Interest and late payment penalties come on top of these. If you keep ignoring them, HMRC can take enforcement action to recover the debt, which can end up in court. Getting organised early is far cheaper. You can see what's included on the Pie Tax pricing page.

Why So Many People Get Caught Out

Most of the 1,000,000 aren't trying to avoid tax. Lee Murphy, managing director of The Accountancy Partnership, told The Sun that the people most likely to be caught out are those who started a business, took on evening freelance work or became landlords. None of them think of themselves as Self Assessment people until a letter from HMRC arrives.

The side income builds up gradually while your main job carries on as normal. Here's why Pie Tax works for people in this position: it's built for people who aren't tax experts and don't want to become one.

Sort It Today, Relax in January

If you have income outside your job, check whether you need to register and do it before the end of today. Then start preparing your return so January isn't a scramble.

Get started today for free and have your Self Assessment ready long before the deadline.

If you'd rather track everything from your phone, download the Pie Tax app and log your side income and expenses as they happen.

Get Started for Free