CIS subcontractors: you have 9 days to set up MTD and most of you do not know it applies to you

The Making Tax Digital deadline is 6 April 2026. Nine days away.

Most of the noise is about IT contractors and tech freelancers. But there is a large group that is completely overlooked in the coverage: CIS subcontractors.

Who this hits

If you work in construction under the Construction Industry Scheme, you are self-employed for tax purposes. That means:

• Your gross CIS payments count toward your qualifying income threshold
• If you earned over £50,000 from self-employment (CIS + any other work) in the last tax year, you are in scope from April 2026
• If you earned over £30,000, you are in scope from April 2027

Those thresholds are gross — before materials, before fuel, before any expenses.

What most CIS subs do not realise

Your CIS deductions do not reduce your qualifying income for MTD purposes.

A labourer earning £55,000 gross with £10,000 CIS deducted gets £45,000 net. But HMRC looks at the £55,000. They are in scope.

This is catching people out.

What you need to do before April 6

1. Check your 2024/25 gross self-employment income (your UTR statements, not your take-home)
2. If over £50,000 — you need to be on MTD-compatible software before April 6
3. Pick software: HMRC has a list. Xero, QuickBooks, FreeAgent, and several niche CIS tools are compatible
4. Link it to your HMRC account via Making Tax Digital signup
5. Start keeping digital records of income and expenses quarterly

The penalty situation

HMRC is not doing a soft launch for people who miss this. Penalties for not keeping digital records start from the first quarter you miss.

They have been clear: ignorance is not an excuse. The deadline has been public since 2023.

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If you want to check your own position quickly, I built a free MTD Readiness Checker — it asks the right questions and tells you exactly where you stand in under 2 minutes.

For CIS contractors who want the full picture — thresholds, software options, what quarterly updates look like, and the penalty schedule — the CIS Contractor MTD Survival Kit (£16) covers all of it in plain English.