Let’s be honest: nobody starts a business because they’re excited about tax returns. You started your business to provide a service, build something cool, or finally be your own boss. But as of April 2026, the goalposts have moved. If you’re a sole trader earning over £50,000, Making Tax Digital (MTD) for Income Tax isn’t just a "maybe" anymore, it’s the law.
At Makes Sense Accountants, we see a lot of people panicking about these changes. HMRC (let's call them the "enemy" for today, shall we?) has introduced a whole new way of working, and with it, a brand-new penalty system that functions a lot like driving license points.
If you don't want to see your hard-earned profits disappearing into HMRC’s coffers via fines, you need to avoid these seven common traps. Here is how to stay on the right side of the rules and keep Tim and the team happy!
The New "Points" System: Why Small Slips Cost Big Money
Before we dive into the mistakes, you need to understand how the "enemy" is keeping score now. HMRC has swapped the old flat-rate late filing penalties for a points-based system.
It works like this:
- Miss a deadline? You get 1 point.
- Reach the threshold? (For quarterly filers, that’s usually 4 points).
- The Hammer Falls: Once you hit that threshold, you’re hit with a £200 fine.
- And it doesn't stop there. Every subsequent late submission after you've hit the threshold triggers another £200 fine.
It’s designed to catch the "serial procrastinators." The good news? Points eventually expire if you stay compliant for a set period. The bad news? If you keep making these seven mistakes, those points will rack up faster than a speeding ticket in a school zone.
1. Thinking "I’ve Got Until 2027"
One of the biggest mistakes we’re seeing right now is people getting their dates mixed up. Yes, if you earn between £30,000 and £50,000, you have until April 2027. But if your qualifying income is over £50,000, the clock has already struck midnight. You are in the MTD era now.
Ignoring the start date is the easiest way to earn your first penalty point. HMRC isn't exactly known for their "oops, my mistake" leniency.
How to avoid it: Check your 2024/25 tax return. If that "Total Income" figure was north of £50k, you need to be on an MTD-compliant system immediately. If you’re unsure, give us a shout for some sole trader self assessment tax return support.
2. The "One Big Pot" Bank Account
We get it. It’s easier to just have one bank account for everything. You buy a new drill for work, then pick up the weekly shop on the way home, all on the same debit card.
Under MTD, this is a nightmare. MTD requires digital links. When you come to do your quarterly updates, you (or your software) have to sift through hundreds of personal transactions to find that one receipt for a box of screws. This leads to errors, and errors lead to inquiries.
How to avoid it: Open a dedicated business bank account. It doesn't have to be fancy. Just keep your "living life" money separate from your "running a business" money. It makes the digital record-keeping process 10x faster and much more accurate.
3. Forgetting the "Quarterly" in Quarterly Updates
For years, the Self Assessment was a once-a-year panic in January. Those days are gone for MTD-enrolled sole traders. You now have to send four quarterly updates to HMRC throughout the year.
The common mistake is thinking these updates are just "rough guesses." While they don't require the complex accounting adjustments you do at year-end, they still need to be an accurate digital summary of your income and expenses.
How to avoid it: Mark these dates in your calendar right now:
- 7 August
- 7 November
- 7 February
- 7 May
Miss one of these, and boom, that’s a penalty point.
Visual Idea: A calendar with four big red circles on the MTD deadline dates.
4. Using "Non-Compatible" Software (or None at All)
You cannot file MTD updates through the old HMRC portal. You also can’t just email them an Excel spreadsheet. HMRC requires you to use "Functional Compatible Software."
We’ve seen people buy software that claims to be for small businesses, only to find out it doesn't actually have the "bridge" to talk to HMRC’s systems. Or worse, people trying to keep paper records and then "typing them in" once a quarter. That isn't "digital record keeping" in the eyes of the law.
How to avoid it: Use industry standards like Xero, QuickBooks, or FreeAgent. At Makes Sense Accountants, we’re pros at setting these up so they do the heavy lifting for you. We can even check if your current setup is MTD ready.
5. The "Digital Gap" (The Receipt Shoebox)
Storing a shoebox of receipts under your bed is no longer a valid accounting strategy. MTD requires a digital trail. If you incur an expense, there needs to be a digital record of it.
The mistake many make is having a digital software but still losing the physical evidence or failing to link the two. If HMRC decides to look into your business (the "enemy" loves an audit), and you can’t show the digital link from the transaction to the filing, you’re in trouble.
How to avoid it: Use an app like Dext or the built-in receipt scanners in your accounting software. Snap a photo of the receipt the second you get it. The software reads the data, stores the image, and links it to your bank feed. No paper, no stress.
6. Not Reconciling Regularly
Wait until the day before the quarterly deadline to look at your books? That’s a recipe for disaster. When you’re in a rush, you miss expenses (meaning you pay more tax than you should) or you categorize things incorrectly.
The beauty of digital accounting is that it’s "real-time." The mistake is treating it like it's still 1995 and only looking at the numbers once a year.
How to avoid it: Spend 10 minutes every Friday morning. Categorize your bank transactions, snap your receipts, and check your "Tax Estimate" in your software. It keeps you in control and ensures your quarterly updates are 100% accurate.
7. The "I Can Do It All Myself" Trap
MTD for Income Tax is significantly more complex than the old Self Assessment system. Between managing digital links, meeting quarterly deadlines, and navigating the new penalty points, it’s a lot for a busy sole trader to handle.
The biggest mistake is thinking an accountant is just an "expense." A good accountant is an investment. We don't just file your returns; we find the tax savings you missed, we shield you from HMRC's "point-scoring" games, and we explain everything in plain English.
How to avoid it: Let the experts handle the technical stuff so you can focus on making money. We’ve seen it all, and we know exactly how to keep the "enemy" at bay while making sure you don't pay a penny more than you legally owe.
Why Makes Sense Accountants?
We get it, tax is boring. It’s confusing, it’s full of jargon, and the rules seem to change every time you turn around. That’s why we’re here.
Tim and the team at Makes Sense Accountants believe that your finances should… well, make sense. We don't talk in codes or hide behind complex tax law. We give you straight-talking advice and partner-led service. Whether you need self-assessment support or a full MTD setup, we’ve got your back.
We create value by:
- Saving you time: No more Sunday nights spent staring at spreadsheets.
- Saving you money: Identifying tax-deductible expenses you didn't know existed.
- Providing peace of mind: We act as your shield against HMRC. If they come knocking, they talk to us, not you.
Don't Wait for the Penalty Points to Pile Up
MTD is here, and the "enemy" is ready to hand out points. Don't let your business become a statistic. Whether you’re just crossing that £50k threshold or you’re worried about the 2027 rollout, let’s get you sorted.
Ready to ditch the jargon and get your tax sorted?
Contact Tim and the team at Makes Sense Accountants today!
We’ll take a look at your current setup, explain the figures in plain English, and make sure Making Tax Digital actually makes sense for your business.