Blog Making Tax Digital

MTD and Side Hustles: Does It Apply to a Second Income?

June 29, 2026 3 min read

Quick answer:

Making Tax Digital can apply to a side hustle if your gross self-employment and property income crosses the qualifying income threshold, and crucially, your employed (PAYE) salary doesn’t count towards that threshold, so only your side income is measured, but the trading allowance means very small side incomes may not be taxable or reportable at all.

If you’ve got a job plus a side income, here’s exactly where you stand.

Does MTD apply to side hustles?

It depends on the size of the side income, not the fact that it’s a side hustle. If your gross self-employment (and any property) income exceeds the threshold, MTD applies, regardless of your day job. Your salary is excluded from the qualifying income calculation. See MTD with multiple income sources and am I affected by Making Tax Digital?

Your salary doesn’t count, so what does?

Only your gross self-employment and property income is measured against the threshold. So if you earn £45,000 in a job and £10,000 from a side hustle, only the £10,000 counts, well below the threshold, so MTD doesn’t apply to the side income yet. But a £35,000 side business would be a different story. Confirm in MTD qualifying income explained.

What about the trading allowance?

If your side income is very small, the trading allowance may mean you don’t even need to report it, or that only the excess is taxable. Once your side income grows beyond that, normal Self Assessment, and eventually MTD, applies. This is where many side-hustlers first need to get organised.

When does a side hustle become “real”?

As your side income grows, you cross thresholds: first into needing to report it at all, then into Self Assessment, then potentially into MTD. Building good habits early means each step is painless. See how to register as a sole trader and bookkeeping for freelancers.

How CleanBooks AI suits side hustles

CleanBooks AI is ideal for a growing side income: connect the account you use for it, let Keeva™ categorise, and watch a live tax estimate build, so you always know what your side hustle owes, and you’re ready the moment it grows into MTD scope. No spreadsheets, minimal time.

Side income getting serious? Get organised with CleanBooks AI free, 6 months free, no credit card.

Frequently asked questions

Does MTD apply to a side hustle?
It applies if your gross self-employment and property income crosses the qualifying income threshold. Your employed salary doesn’t count towards that threshold, so only the side income is measured. Small side incomes below the threshold aren’t yet in MTD.
Does my salary count towards MTD if I have a side hustle?
No. Employment (PAYE) income is excluded from MTD qualifying income. Only your gross self-employment and property income is measured against the threshold, regardless of how much you earn from a job.
Do I need to report a small side income?
Possibly not, if it’s within the trading allowance. Above that, you generally need to report it via Self Assessment, and if it grows beyond the MTD threshold, MTD applies. Keeping records early makes each step easier.
What is the trading allowance?
The trading allowance is a tax-free allowance for small amounts of self-employment or casual income. If your side income is within it, you may not need to report it; above it, normal reporting rules apply.

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