How To Submit 2 Years Worth Of Tax: A Complete Guide

Alan Bermingham

10 Years of Expertise in Fintech Innovation

3 min read

Introduction

Missing one tax deadline is stressful enough but two years' worth of returns? That's when the panic really sets in.

Whether you've been self-employed and life got in the way, you forgot to register, or you simply didn't realise you needed to file, catching up on back taxes feels overwhelming. The good news is that HMRC expects people to fall behind occasionally, and there's a clear process to get back on track.

You'll face penalties, sure, but submitting late is always better than not submitting at all.

If you'd rather hand the whole thing over to someone who can sort it quickly, Pie tax the UK's first personal tax app handles back filing and connects you directly with HMRC-registered agents. Or if you're just here to get to grips with it all, let's break it down!

Understanding What "2 Years Worth of Tax" Really Means

When we talk about submitting two years of tax, we’re usually referring to two separate Self Assessment tax returns. Each tax year runs from 6 April to 5 April the following year, and each one gets its own return for the previous tax year.

If you’re catching up in November 2025, you might owe returns for the previous tax years 2022/23 and 2023/24. For example, if you missed filing for both 2022/23 and 2023/24, you would need to submit two separate returns to cover those periods.

Each return covers income, expenses, and any tax you owe for that specific 12-month period.

You can’t combine two years into one submission HMRC needs them separately. Even if you earned nothing in one of those years, you still need to file if you’re registered.

The longer you wait, the higher the penalties climb. Each year’s return has its own deadline, typically the date of 31 January following the end of the tax year, so it’s important to know the exact date for each tax return deadline to avoid penalties.

Woman working in her laptop checking her updates in 2 years worth of tax

The Exact Steps to Submit Your Back Tax Returns

Right, let’s get practical here’s how you actually submit those overdue returns to HMRC. The process is the same whether you’re one day late or two years behind, just with escalating penalties.

First, register for Self Assessment if you haven’t already at gov.uk/register-for-self-assessment. Wait for your Unique Taxpayer Reference (UTR) to arrive by post this takes about 10 days.

Set up your Government Gateway account online so you can log into HMRC’s digital services. Gather all your income records, including profit figures for each year, expense receipts, and bank statements for both tax years. If you do not have previous tax records, you may need to request them from HMRC.

File the oldest return first through HMRC’s online system or using commercial software. Submit the second year’s return immediately after don’t wait for the first one to be processed. If your return is late, remember that after three months, daily penalties will apply.

Self Assessment Tax and Compliance

Staying compliant with Self Assessment tax rules is crucial for anyone who needs to file tax returns in the UK. Compliance means more than just submitting your assessment tax return on time it’s about making sure every detail is accurate, paying any tax you owe by the deadline, and keeping thorough records for each tax year. Whether you’re dealing with previous years, late returns, or amendments, keeping your tax affairs in order helps you avoid unnecessary penalties and interest charges.

If you miss a deadline or fail to file, HMRC can charge interest on late payment and issue late filing penalties. The longer you wait, the more these can add up, especially if you have multiple years outstanding.

It’s important to know your tax return options, such as filing online or sending a paper copy, and to respond promptly to any notices or requests from HMRC. If you receive a determination or assessment, review it carefully and seek advice if you think there’s a mistake.

By staying organised, submitting accurate returns, and paying your self assessment tax on time, you’ll avoid the stress of late returns and keep your tax affairs running smoothly. If you ever feel overwhelmed, professional advice is just a call or click away don’t wait until the penalties start piling up.

Man working on his computer checking his report

Penalties and Interest: What You'll Actually Pay

Let’s talk money, because understanding the penalty structure helps you decide how quickly to act. If you have failed to file your Self Assessment tax return by the deadline, penalties apply automatically under the law. HMRC’s penalty system is automatic and increases the longer you delay.

The initial late filing penalty is £100 per return, even if you owe no tax. After 3 months late, you pay £10 per day for up to 90 days that’s another £900 maximum.

For example, if you filed your return 6 months late, you would owe the initial £100, plus up to £900 for daily penalties, and an additional £300 or 5% of the tax due, whichever is higher.

After 6 months, there’s an additional penalty of £300 or 5% of the tax due, whichever is higher. After 12 months, you face another £300 or 5% penalty on top of everything else.

If penalties are due, HMRC will send a notice to inform you. A person who receives a penalty can appeal if they have a reasonable excuse, and the First Tier Tribunal will consider the case. To ensure you are fully informed, investigating this area is a smart move: overturning computer generated fines.

Getting Help When You're Overwhelmed

If the thought of tackling two years of returns makes you want to hide under the duvet, you're not alone. Professional help exists specifically for situations like yours.

Accountants who work with back filing can sort both years in a matter of days. HMRC's own helpline (0300 200 3310) can talk you through the process step by step.

Many tax software platforms offer guided support for catching up on multiple years. If you genuinely can't afford the penalties, you can request a "reasonable excuse" appeal.

Pie tax connects you with HMRC-registered agents who handle the entire catch-up process. Some accountants offer fixed-fee catch-up packages that include both filing and penalty negotiation.

Don't suffer in silence getting help is often faster and less stressful than going it alone.

Young man searching about how to submit 2 years worth of tax

Why You Might Need to Submit Two Years at Once

Life happens, and there are loads of legitimate reasons people fall behind on their tax returns. Understanding why you’re in this position helps you avoid it happening again. Many find it helpful to consult external resources regarding the paradox of strong wage growth.

If you have failed to file your tax return, HMRC may issue a notice or send a letter requiring you to submit your outstanding returns. Under UK law, every person required to file a Self Assessment tax return must do so, regardless of circumstances.

I once met a photographer who’d been shooting weddings for three years before realising her “side hustle” needed tax returns. She ended up filing four years at once stressful, but manageable once she got started.

Sometimes people register late with HMRC and now need to catch up on previous years. Or maybe you’ve been avoiding it because you’re worried about what you might owe. Whatever the reason, you’re not alone and there’s a way forward.

Pie tax: Simplifying Back Tax Filing

Catching up on missed tax returns doesn't have to consume your entire month. Pie tax the UK's first personal tax app offers real-time tax calculations as you enter your income, so you'll know exactly what you owe before you submit.

Our sector-specific assistants guide you through expenses and allowances you might have missed, potentially reducing your bill. The multiple-income dashboard makes it easy to see all your earnings in one place, even across complicated years Gaining clarity on these rules is crucial; you can find more details under how freelancers are affected next year.

If you've got receipts everywhere and no bookkeeping system, our automated tools organise everything ready for submission. Once you're done, you can file directly to HMRC through the app without switching platforms.

Explore the Pie tax app if you'd like to see how it works catching up doesn't have to be complicated.

Young man focused working on his tax report

Final Thoughts

Submitting two years worth of tax returns isn't fun, but it's absolutely doable, and you'll feel massively relieved once it's done. The penalties sting, but they stop accumulating the moment you file.

Start with the oldest return, gather your paperwork methodically, and remember that HMRC would rather you filed late than not at all. If you're stuck, get professional help and move forward.