Self-Employed and a Landlord? How MTD Treats Mixed Income

Plenty of landlords don't just let property. You might fix boilers during the week and rent out a flat on the side. You might run a hairdressing chair, do freelance design, or sell on a market stall — and also collect rent from a buy-to-let.

If that's you, Making Tax Digital can feel doubly confusing. Two income streams, two sets of rules? Not quite. The good news is that MTD has a fairly logical way of handling this, and once you see how the numbers fit together it stops being scary.

The threshold looks at everything together

The first thing to understand is how you get pulled into MTD at all.

MTD for Income Tax is being phased in by what HMRC calls your qualifying income. That's your gross income — turnover before you take off any expenses — across both self-employment and property combined.

The dates are:

• over £50,000: from 6 April 2026
• over £30,000: from 6 April 2027
• over £20,000: from 6 April 2028

Below £20,000, you're not required to join yet.

The key word is combined. People often assume each income source is measured on its own, so they relax because neither their business nor their rent tops the threshold by itself. That's a costly misunderstanding.

A worked example: Priya the plumber

Let's say Priya runs a plumbing business and also lets out a one-bedroom flat.

• Her plumbing turnover is £38,000 a year (before van costs, materials, anything).
• Her flat brings in £14,400 a year in rent (before letting fees, repairs or insurance).

Looked at separately, neither figure crosses £50,000. But MTD doesn't look at them separately. It adds them:

£38,000 + £14,400 = £52,400 of qualifying income.

That's over £50,000, so Priya is in the first wave — she'll need to follow MTD from 6 April 2026. If she'd only glanced at each stream on its own, she'd have been caught out.

Note we used the gross figures. Priya's actual taxable profit might be far lower after expenses, but the threshold doesn't care about profit. It's turnover that counts. You can read more on how this works in our guide to MTD income thresholds.

Two streams, two sets of records — but one rhythm

When you're in MTD, you keep digital records of income and expenses, send HMRC four quarterly updates a year, and finish with one final declaration after the tax year ends. Together these replace the old Self Assessment return for that income.

Here's the part that trips people up: self-employment and property are treated as separate sources within MTD. So Priya keeps her plumbing income and expenses in one place, and her rental income and expenses in another. They don't get mixed into a single pot.

The upside is that the timing is shared. Both sources follow the same quarterly periods, ending 5 July, 5 October, 5 January and 5 April, with updates due by 7 August, 7 November, 7 February and 7 May. You're not juggling two different calendars — just submitting figures for each source on the same dates.

From 2025–26 onwards those quarterly updates are cumulative, meaning each one is a running year-to-date total rather than a standalone three months. If you made a mistake earlier in the year, the next update naturally corrects it. Our guide to MTD deadlines lays the dates out in full.

How a quarter actually looks for Priya

By the second quarter (the period ending 5 October), Priya's cumulative position might be:

Plumbing

• Income to date: £19,000
• Expenses to date: £6,200

Property

• Income to date: £7,200
• Expenses to date: £1,400

She submits both sets of year-to-date totals by 7 November. Two sources, one deadline, no separate Self Assessment form for either. When the tax year closes, she ties everything together with a final declaration, due by 31 January following the end of the tax year — the same date Self Assessment always used.

That final declaration is where you confirm the full picture, add anything outside MTD (like savings interest or dividends), claim reliefs, and tell HMRC "this is correct." If you've also got income beyond business and property, our guide on MTD when you have other income is worth a look.

What about a jointly-owned flat?

Worth a quick note if your property is shared. Jointly-owned rental income is split by ownership share, and the threshold is measured per person. So if Priya owned that flat 50/50 with her partner, only her half of the £14,400 — £7,200 — would count towards her qualifying income.

That changes her sum: £38,000 + £7,200 = £45,200, which is under £50,000. She'd then fall into a later wave depending on where she lands against the £30,000 and £20,000 thresholds in following years.

Do you need an accountant for this?

Mixed income makes people reach for the phone to an accountant, and that's a perfectly reasonable choice. But it isn't compulsory. The mechanics are repetitive once set up: record as you go, check the quarterly totals, submit.

Software like Quarterwise is built to keep your property records tidy and file your quarterly updates and final declaration to HMRC — designed for landlords rather than accountants. If you do prefer professional help, you can still work alongside an accountant using the same digital records.

The heart of it: don't measure your streams in isolation. Add them up, check the date, and keep little and often.

This is general information, not tax advice. Always check your own position with HMRC or a qualified accountant.