Take a deep breath. If you are a sole trader who clicked "submit" on your very first Making Tax Digital (MTD) quarterly update by the August 7th deadline, give yourself a pat on the back. You've officially entered a brand-new era of digital tax reporting.
For months, the talk has been all about preparation, software setup, and navigating digital record-keeping. But now that the dust has settled on quarter one, a very common question is echoing across home offices and workshops nationwide: “Okay, I’ve submitted it… but did I actually do it right?”
If you suspect something might have gone slightly sideways: or if you’re worried that a rushed submission might come back to haunt you before the next deadline: you are definitely not alone. The first quarter was a steep learning curve for everyone.
In this guide, we’ll break down the most common mistakes sole traders made in their first MTD quarterly update, what HMRC’s rules actually mean for you right now, and how to tidy up your books before the next submission rolls around. No confusing accountant jargon: just practical, friendly advice.
1. The "Soft Landing" Myth vs. Reality
One of the biggest misconceptions floating around after the August 7th deadline is that HMRC’s transitional rules (often called the "soft landing period") mean anything goes.
While it's true that HMRC has introduced penalty leniency for the first year of MTD for ITSA (Income Tax Self Assessment): meaning you generally won't receive points-based penalties for minor quarterly reporting errors: it does not mean you can ignore accuracy altogether.
Late-payment penalties and final declaration rules still apply, and building messy habits now will only multiply your stress when year-end approaches. Think of this first quarter as your dry run. Spotting errors now is the ultimate win because it stops small glitches from compounding into major headaches.
2. Mistake #1: Treating Quarterly Figures Like a Blank Slate
If there was one award for the most frequent first-time mistake, it would go to misunderstanding cumulative figures.
Many sole traders assumed that each quarterly update only needed to include the income and expenses generated strictly within those three months. When preparing their submission, they reset their figures to zero, forgetting that MTD quarterly updates are cumulative year-to-date reports.
- The Fix: Your software should handle this automatically if it's set up correctly, but always double-check. When you file your next update, your figures must include everything from the start of your accounting year up to the end of that specific quarter, not just the recent 90 days. If you made this mistake in Q1, don't panic: you can correct your cumulative totals in your next software sync before the next deadline.
3. Mistake #2: Blurring the Lines Between Personal and Business Expenses
When you're busy running your business, it’s remarkably easy for personal spending to slip into your business bank feed. Did that coffee run on Saturday get categorized as a business expense? Did you accidentally include a personal subscription?
HMRC's digital matching tools are sharper than ever. Leaving personal transactions inside your business records: or miscategorising general expenses into the wrong HMRC buckets (like putting office costs under professional fees): is a recipe for compliance flags down the road.
- The Fix: Take 15 minutes each week to review your bank reconciliation. Separate your personal and business spending cleanly. If you need a refresher on how to keep things crystal clear, read our guide on Sole Trader Accounting Services to see how simple good habits save time.
4. Mistake #3: Mixing Multiple Income Streams
Many sole traders don't just have one income stream: they might run a primary freelance business while also bringing in property rental income, or manage two distinct trading activities.
A common pitfall in the first round was lumping all these different income sources into a single quarterly update. HMRC treats each distinct trade and property business as separate entities that require their own individual reporting.
- The Fix: Ensure your MTD software correctly separates your income streams. Each business activity has its own reporting obligations and thresholds. If your total gross income crosses the threshold, you must ensure every stream is accounted for in its proper digital pigeonhole. You can learn more about how the rules apply by exploring our hub on Making Tax Digital.
5. Mistake #4: Software Glitches and Missing Digital Records
Did you struggle to connect your bank feed right before the deadline? Did you rely on manual spreadsheets without proper bridging software?
HMRC doesn't accept random paper notes or unstructured estimates for MTD. You need a clear chain of digital records connecting your original invoices and receipts all the way through to your final submitted figures.
- The Fix: If your software gave you a headache this time around, take action now while the experience is fresh. Switch to an HMRC-recognised platform that automates bank feeds and receipt scanning, or speak with an advisor who can set up a seamless system for you. For a quick recap of how the August timeline played out, take a look back at our First Quarterly Update Quick Start Guide.
Action Plan: How to Prepare for the Next Deadline
Now that you've survived your first submission, here is your simple 3-step action plan to make the next quarterly update completely stress-free:
- Review Your Categories: Log into your accounting software today and check that last quarter's expenses were sorted into the correct HMRC categories.
- Reconcile Weekly, Not Quarterly: Don't leave your bookkeeping until the week before the deadline. Spend 10 minutes every Friday matching your bank transactions.
- Talk to an Expert Early: If you felt lost during your first submission, you don't have to figure out the rest of the year alone. Getting professional guidance now saves hours of guesswork later.
Remove the Stress From Your Next MTD Update
Getting your first MTD quarterly update out of the way is a major milestone, but you don't have to navigate the digital tax landscape by yourself. At Makes Sense Accountants, we explain figures in plain English: no confusing jargon, no hidden fees, and zero accounting mumbo-jumbo.
Whether you need help cleaning up your software settings, reviewing your categories, or handing over the entire MTD process so you can focus on running your business, we are here to help.
Ready to make your next tax deadline completely stress-free? Get in touch with our team today through our contact page, and let’s talk about how we can support your sole trader business.