How Rushing a Tax Return Leads to Long-Term Issues (Impact)

How Rushing a Tax Return Leads to Long-Term Issues (Impact)
Charlotte Baroukh

Charlotte Baroukh

Tax Expert @ Pie

3 min read

Updated: 20 Jan 2026

3 min read

Updated: 20 Jan 2026

Read before you file

The deadline is looming, your paperwork's scattered, and HMRC waits for no one. Every year, millions of Britons find themselves in this last-minute tax scramble.


While rushing isn't ideal, there are smart ways to complete your return quickly without costly mistakes. With the right approach, you can turn tax panic into organised action.


The UK's first personal tax app, Pie tax, handles pressure situations brilliantly with automatic calculations that save hours during crunch time. Or if you're just here to get to grips with it all, let's break it down!

What exactly counts as rushing your tax return?

Most tax pros would consider any Self Assessment submitted within two weeks of the 31 January deadline as "rushed". This typically means forms filled hastily without proper document review.


It's when you're prioritising speed over accuracy, perhaps due to poor planning or unexpected life events. The classic signs include completing sections from memory rather than documentation.


You might find yourself skipping double-checks and battling that sinking feeling that you've missed something important. I once submitted my return at 11:47 pm on deadline day, frantically searching for a missing dividend statement.

Article supporting image

Why do so many of us end up racing against the HMRC clock?

Procrastination is the number one culprit. Let's be honest tax returns aren't exactly thrilling weekend entertainment! Many people wait for missing documents from employers, banks, or clients before starting. These often arrive frustratingly late in January, leaving little time to process them properly.


Unexpected life events like illness, family emergencies, or work crises can throw even the most organised tax plans into disarray. The pandemic has only amplified these disruptions for many taxpayers.


There's also widespread confusion about what's actually needed. This leads many to delay until they "have time" to figure it all out time that mysteriously vanishes as January progresses.

Essential information you'll need to hand

Your National Insurance number and Unique Taxpayer Reference (UTR) are absolute musts. Without these, you can't even access the system properly to begin filing.


Gather all income statements: P60s, P45s, freelance invoices, and bank statements showing interest. Don't forget details of any rental income or dividends received during the tax year.


For the self-employed, you'll need business expenses organised by category. Keep receipts ready to back them up if questioned later by HMRC. Records of pension contributions, Gift Aid donations, and any tax relief you're entitled to claim are crucial. These can significantly reduce your tax bill even when rushing.

Additional supporting image

Quick filing strategies that actually work

Set aside a solid block of uninterrupted time with a reliable internet connection. This isn't something to tackle during your lunch break or with patchy Wi-Fi!


Use last year's return as a template if your situation hasn't changed dramatically. This can save loads of time on the basic sections that remain consistent year to year.


Focus on accuracy over speed for the big numbers income, major expenses, and pension contributions. These are what HMRC scrutinises most closely during reviews.


If truly pressed for time, consider filing a basic return now to meet the deadline. You can submit an amendment later, avoiding late filing penalties while giving yourself breathing room.

Common mistakes when rushing your return

Mathematical errors top the list when filing in haste. Rushing often means skipping double-checks on your calculations, which can lead to overpaying or triggering investigations.


Missing valuable deductions happens frequently when in a hurry. Tax relief for things like working from home or professional subscriptions gets overlooked in the rush.


Entering information in the wrong sections is surprisingly common and causes major headaches. The HMRC form isn't always intuitive, especially when you're under pressure.


Many rushed filers forget to budget for actually paying the tax due. This leads to a nasty surprise when they realise they need to find potentially thousands of pounds within weeks.

Article supporting image

What to do if you can't meet the deadline

Contact HMRC immediately if you know you'll miss the deadline. They're much more understanding if you reach out before rather than after the cut-off date.

Prepare a 'reasonable excuse' explanation if you have genuine grounds. Serious illness, bereavement, or system failures are considered by HMRC when reviewing penalty appeals.


Understand the penalties: £100 immediately for missing the deadline, then escalating charges the longer you delay. Knowing what you're facing helps with planning your next steps.

Remember you can request a Time to Pay arrangement if you'll struggle with your tax bill. HMRC often agrees to reasonable payment plans when approached professionally.

Final Thoughts

Rushing your tax return isn't ideal, but sometimes life happens. When pressed for time, focus on accuracy with the big numbers and gather as much documentation as possible.


Remember that penalties for errors can exceed those for late filing. If you're truly unprepared, contacting HMRC before the deadline is often the better option.

The simplest solution for next year? Start early and stay organised with monthly record-keeping. Or use specialised tax tools that make the whole process less daunting.

Additional supporting image

Pie tax: Simplifying Last-Minute Tax Returns

Even the most organised people sometimes find themselves rushing against HMRC deadlines. Pie tax was designed with these pressure moments in mind. Our real-time tax calculations update as you enter information. This eliminates the need for double-checking complicated maths when time is tight.


The multiple-income dashboard organises all your revenue streams instantly. This prevents costly omissions when racing against the clock in those final January days.


Direct HMRC filing cuts out unnecessary steps, potentially saving hours during those crucial final days before the deadline. The intuitive interface guides you through each section efficiently. Fancy seeing how it works? Explore the Pie tax app if you'd like less stress with your next tax return.


Want to get smarter about taxes?

The Tax Pible has tax tips, guides, video tutorials, and expert insights.


Stay up to date with the latest tax news and watch the UKs first tax podcast - the Piecast

Want to get smarter about taxes?
Whatsapp Pie Tax