If you’re a heating engineer or plumber running your own business, you’ve probably heard the phrase “Making Tax Digital” bouncing around. Maybe your accountant mentioned it. Maybe you saw something on a trade forum. Maybe you’ve been quietly hoping it doesn’t apply to you.
Here’s the honest truth: if you’re a sole trader whose 2024 to 2025 tax return showed income over £50,000, it already applies to you, and it has done since April 2026. If you earn less, your turn is coming. But don’t panic. Think of this like a boiler service — it’s much easier to deal with when you plan ahead rather than scrambling when something breaks down.
Let’s walk through exactly what Making Tax Digital means for your plumbing or heating business, what you need to do, and how to get yourself sorted before your start date, whether that was April 2026 or is still to come.
What Does Making Tax Digital Actually Mean?
In plain English, Making Tax Digital (MTD) is HMRC’s plan to move the entire tax system online. No more paper records stuffed in a shoebox. No more scribbling figures on the back of an envelope and handing it to your accountant once a year.
Instead, you’ll keep digital records of your income and expenses using approved software, and you’ll send summary updates to HMRC throughout the year. That’s it. No secret formula. No trick.
Consider this: you already do something similar every time you use an app to send a quote or track a job. MTD is just applying that same logic to your tax records. The difference is that the software talks directly to HMRC on your behalf.
MTD Started in April 2026: Who Is In and When?
From 6 April 2026, MTD for Income Tax Self Assessment (MTD for ITSA) became mandatory for sole traders and landlords whose 2024 to 2025 tax return showed qualifying income over £50,000. Qualifying income is your total income from self-employment and property added together, before expenses. It is not your profit.
The threshold then drops each year, and it is always based on the tax return you sent in the year before:
- From 6 April 2026: qualifying income over £50,000 on your 2024 to 2025 return
- From 6 April 2027: qualifying income over £30,000 on your 2025 to 2026 return
- From 6 April 2028: qualifying income over £20,000 on your 2026 to 2027 return
If you’re a self-employed heating engineer turning over more than £50k a year, you should already be using it. If your income sits between £30,000 and £50,000, you have a little more breathing room, as your start date is April 2027. But getting set up now makes far more sense than leaving it to the last minute.
What Happens If You Miss It?
HMRC aren’t messing about with this. If you’re not compliant, you could face:
- Late submission penalties — a points-based system where each missed quarterly update or tax return earns you a penalty point. Reach 4 points and you’ll get a £200 penalty, with further penalties if you keep missing deadlines. HMRC has confirmed it will not give penalty points for late quarterly updates in the 2026 to 2027 tax year, the first year. You still have to send every update before you can file your tax return, and a late tax return still gets a point.
- Late payment surcharges — if you owe tax and don’t pay on time, interest and surcharges kick in.
- Inaccuracy penalties — if your digital records don’t match what you’re submitting, HMRC can apply penalties based on the amount of tax understated.
In my eyes, the real cost isn’t even the fines. It’s the stress and disruption of trying to sort everything out in a rush while you’re busy fitting boilers and chasing emergency call-outs.
Who Exactly Is Affected?
Let’s be specific, because there’s a lot of confusion floating around online.
From April 2026: Sole trader plumbers, heating engineers, gas engineers, and any self-employed trade professional with qualifying income over £50,000 on their 2024 to 2025 tax return.
From April 2027: The threshold drops to £30,000, pulling in a much larger group of sole traders.
From April 2028: The threshold drops again to £20,000.
If you trade through a limited company, MTD for ITSA doesn’t apply to you yet. HMRC has separate plans for limited companies further down the line. But if you’re weighing up whether to stay sole trader or go limited, now is a good time to get proper advice. We’ve written more about the differences in our guide to sole trader vs limited company for trades.
One thing worth noting: if you have multiple income sources — say you’re self-employed and you also rent out a property — the thresholds look at your combined gross income across all sources.
What Software Will You Need?
To comply with MTD, you’ll need HMRC-recognised software that can keep digital records and submit your updates electronically. You can’t just use a spreadsheet on its own anymore.
At Together We Count, we recommend Xero for our plumbing and heating clients. Here’s why:
- It’s built for small businesses — the interface is clean and straightforward, not designed for corporate finance teams.
- Bank feeds pull in automatically — connect your business bank account and transactions appear in Xero without you typing anything.
- Receipt capture from your phone — snap a photo of a merchant receipt when you pick up parts from the wholesaler and Xero reads it for you.
- MTD-compatible — Xero is already fully approved for MTD for VAT and is ready for MTD for Income Tax.
- Your accountant can see everything in real time — no more emailing spreadsheets back and forth.
If you haven’t moved to cloud accounting yet, this is your push. We’ve covered the full benefits in our cloud accounting guide for trade businesses.
The key point is this: the software does the heavy lifting. You feed in the information, and it handles the formatting and submission to HMRC. It’s no different to using an app to manage your job schedule — once you get into the habit, you wonder how you managed without it.
Quarterly Reporting: What Does That Actually Involve?
This is the part that worries most heating engineers. The idea of reporting to HMRC four times a year sounds like a mountain of extra work. Let me talk you through what it actually looks like.
Under MTD for ITSA, you’ll send four quarterly updates to HMRC each tax year, followed by your tax return:
- Quarter 1 (6 April to 5 July): due by 7 August
- Quarter 2 (6 July to 5 October): due by 7 November
- Quarter 3 (6 October to 5 January): due by 7 February
- Quarter 4 (6 January to 5 April): due by 7 May
- Tax return: your final figures for the year, due by 31 January following the end of the tax year
Each quarterly update is a running total of your income and expenses from 6 April to the end of that quarter. If nothing happened in a quarter, you still need to send an update. If your records are up to date in Xero, this is essentially a button press. Your accountant can even submit these on your behalf.
Think of it like servicing a boiler every quarter instead of waiting for a full breakdown at the end of the year. Smaller, regular check-ins mean fewer nasty surprises when your tax bill lands.
Your MTD Preparation Checklist
Here’s what you need to do, step by step, to make sure you’re ready before your start date. Print this off. Stick it on the van dashboard. Whatever works.
- Check whether you’re above the threshold. Look at the qualifying income on your last tax return (self-employment and property income before expenses). Over £50,000 on your 2024 to 2025 return means you should already be using MTD. Over £30,000 on your 2025 to 2026 return means you start in April 2027, so start preparing now.
- Get set up on MTD-compatible software. If you’re not already using Xero or another approved platform, now is the time. Don’t wait until March 2027 when everyone else is scrambling. Your accountant can help you choose and get started.
- Connect your business bank account. Link your bank to your software so transactions pull through automatically. This alone saves hours of manual entry each month.
- Digitise your existing records. If you’ve been keeping paper records, you’ll need to move everything into your digital system. Start with the current tax year and work forward.
- Set up a routine for recording income and expenses. Get into the habit now. Every Friday afternoon, spend 15 minutes reviewing the week’s transactions. It becomes second nature quickly.
- Register for MTD for ITSA with HMRC. You’ll need to sign up through your Government Gateway account. Your accountant can handle this as part of your agent authorisation, so you don’t need to wrestle with the HMRC website yourself.
- Talk to your accountant about your quarterly submission schedule. Agree who’s doing what. Will you keep the records and they submit? Will they manage the whole process? Get this nailed down now so there’s no confusion come April.
How Together We Count Helps You Prepare
We work with plumbing and heating businesses across Sheffield and beyond. We understand the way your business works — the seasonal fluctuations, the material costs that shift from month to month, the mix of domestic and commercial jobs.
That specialist understanding matters when it comes to MTD. Setting up your software correctly from the start means your quarterly updates are accurate and your categories make sense for a trade business, not a generic template designed for an office-based consultancy.
Here’s what we do for clients getting MTD-ready:
- Software setup and migration — we get you onto Xero with everything configured properly for your trade.
- Bank feed connections — linked up and tested so transactions flow through smoothly.
- Training and support — we show you how to use the software day-to-day, in plain English, with none of the accounting waffle.
- Quarterly submissions — we can handle the reporting for you, so you can focus on doing what you do best.
- Ongoing compliance monitoring — we keep an eye on deadlines and flag anything that needs attention before it becomes a problem.
We don’t just set you up and leave you to it. We stick around.
What About CIS? How Does MTD Fit Alongside Your Existing Obligations?
If you do subcontract work or hire subcontractors yourself, you’re already dealing with the Construction Industry Scheme (CIS). The good news is that MTD doesn’t replace CIS — they run alongside each other.
But it does mean you need your software set up to handle both. CIS deductions need to be recorded properly in your digital records, and your quarterly MTD updates need to reflect those deductions accurately.
This is one of the areas where having an accountant who understands trade businesses really pays off. Getting CIS and MTD working together in your software isn’t difficult, but it needs to be done right from the outset. We’ve covered CIS in more detail in our guide to CIS for plumbing and heating businesses.
If you’re currently having CIS deductions taken from your payments by main contractors, those deductions can be offset against your tax bill. Under MTD, this all needs to be tracked digitally and reflected in your quarterly updates. It’s another reason to get your bookkeeping system properly configured now, rather than trying to untangle it later.
The Bottom Line
Making Tax Digital isn’t optional, and it isn’t going away. But it doesn’t have to be a headache either.
If you start preparing now, you’ll barely notice the change when your start date arrives. Your records will be cleaner, your tax position will be clearer throughout the year, and you’ll spend less time chasing paperwork and more time running your business.
The engineers who leave it until the last minute? They’re the ones who end up stressed, facing penalties, and paying more to get everything sorted in a rush. Don’t be that engineer.
Want to make sure you’re MTD-ready? Get in touch for a free preparation review.
We’ll look at where you stand right now, what needs to happen before April, and put together a clear plan to get you compliant without any drama.