From Self Assessment to Quarterly MTD: What's Changing for UK Business Owners

By Sam

If you are a sole trader or a landlord in the UK, the way you interact with HMRC is currently undergoing its biggest transformation in decades. For years, the "January panic" was a staple of the British business calendar: a frantic scramble for receipts and bank statements as the 31st January deadline loomed.

But as of July 2026, the landscape has fundamentally shifted. We are now officially in the era of Making Tax Digital (MTD) for Income Tax Self Assessment (ITSA). For many, the first major deadline is just weeks away on 7th August.

At Accountant Search, we’ve seen first-hand how this transition is affecting small business owners. While the change can feel overwhelming, it’s designed to bring more transparency and accuracy to your finances. In this guide, we’ll break down exactly what has changed, what hasn't, and what you need to do to stay compliant and stress-free.

The End of the "Once a Year" Mindset

For nearly thirty years, Self Assessment was an annual event. You looked backward at a year that had already finished, often trying to remember expenses from 18 months prior.

Making Tax Digital changes the "when" and "how" of reporting. Instead of one big tax return, you now provide smaller, more frequent updates. This shift from annual to quarterly reporting is intended to reduce the "tax gap": the difference between the tax HMRC expects and what is actually paid: often caused by simple human error or lost paperwork.

By moving to a digital-first system, HMRC wants business owners to have a real-time view of their tax liability. No more nasty surprises in January; with MTD, you should know exactly what you owe as you go through the year.

Who Is Affected and When?

The rollout of MTD for ITSA is happening in phases. Depending on your income levels, you might already be in the system, or you might have a little more time to prepare.

1. From 6 April 2026 (The Current Phase): Mandatory for sole traders and landlords with a combined qualifying income of over £50,000. If your turnover in the 2024/25 tax year exceeded this, you should already be keeping digital records and preparing for your first quarterly update.

2. From 6 April 2027: The threshold drops to £30,000. This will bring hundreds of thousands more SMEs into the fold.

3. The August 7th Milestone: If you were mandated to join this April, your first quarterly update (covering the period from 6 April to 5 July) is due by 7 August 2026.

If you're unsure where you fit or which software to use, it's worth checking out our guide on MTD bridging software vs full apps to see which path suits your turnover and complexity.

What Changes in Practice?

The "how-to" of your daily business life will change in two significant ways: digital record-keeping and quarterly submissions.

1. Digital Record-Keeping

You can no longer keep your records in a shoebox or even a simple manual ledger. MTD requires "digital links." This means your income and expenses must be recorded in MTD-compatible software. While spreadsheets are still allowed, they must be "digitally linked" to HMRC via bridging software. However, most businesses are finding that moving to online business accountants and using cloud platforms like Xero, QuickBooks, or FreeAgent is much simpler.

2. Quarterly Updates

Instead of one tax return, you now have five main touchpoints with HMRC:

• Four Quarterly Updates: These are summaries of your business income and expenses. They don't require complex accounting adjustments (like capital allowances), just a digital snapshot of your transactions.

• The Final Declaration: This happens at the end of the tax year. This is where you (or your accountant) add in things like tax reliefs, personal income from other sources, and final adjustments. This replaces the old SA100 Self Assessment form.

What Stays the Same?

Despite the noise surrounding MTD, several core elements of the UK tax system remain untouched. If you've heard conflicting advice, our guide to Busting 5 Myths About Making Tax Digital for Income Tax clears up some of the most common misconceptions:

• Payment Dates: You still pay your tax on 31 January and 31 July (payments on account). The quarterly updates are for reporting information, not for making immediate tax payments.

• Tax Rules: The actual rules on what you can claim as a business expense haven't changed. If it was "wholly and exclusively" for business before, it still is now.

• The 31 January Final Deadline: You still have until 31 January after the tax year ends to finalize your figures and submit your Final Declaration.

Practical To-Do List for the Transition

If you are feeling the pressure of the new quarterly rhythm, follow these four steps to get back on track. If you are still unsure about the deadline risks, read MTD 2026: What Happens If You Don't Have Bridging Software by the Deadline.

1. Check Your Software Compatibility

HMRC will only accept submissions through approved software. If you are still using desktop software from five years ago, it likely won't work. Verify that your current provider is MTD-ready or look into modern cloud alternatives.

2. Separate Your Finances

If you haven't already, now is the time to ensure your business and personal banking are completely separate. MTD is much easier to manage when you aren't filtering out grocery shopping from your business equipment purchases.

3. Move to Real-Time Logging

Don't wait until the end of the quarter to upload your receipts. Use apps to snap photos of receipts as you get them. This keeps your digital records up to date and makes the quarterly update a five-minute job rather than a weekend chore.

4. Consult a Professional

The complexity of MTD means that having a qualified accountant is more valuable than ever. They can ensure your "Final Declaration" is accurate and help you navigate the new software requirements. If you're looking for help, our SME guide to small business tax services provides a great starting point for comparing your options.

The Benefits of the Shift

While "more reporting" rarely sounds like a benefit, there are genuine advantages to the MTD system for UK business owners:

• Better Cash Flow Management: By seeing your tax liability build up quarterly, you can set aside the right amount of money rather than guessing.

• Fewer Errors: Digital systems flag potential mistakes before you submit them, reducing the risk of HMRC enquiries.

• Increased Productivity: Once the initial learning curve is over, automated bank feeds and digital receipt scanning actually save time compared to manual data entry.

How Accountant Search Can Help

Navigating the transition from annual Self Assessment to quarterly MTD can be daunting, but you don't have to do it alone. At Accountant Search, we specialise in matching SME businesses with the perfect accounting partner.

Whether you need a local expert to help you set up your digital records or a specialist tax advisor to handle your quarterly submissions, we can find the right fit. Don't wait until you're facing a late-submission penalty: start your search today using our small business accountant checklist to find the support you need for the digital age.

The era of Making Tax Digital is here. By embracing the change now, you can turn a compliance burden into a tool for better business growth. For a broader look at your options, see Accounting Services UK: The Complete Guide.