Your contractor still deducts 20% or 30% before you're paid, exactly as before. What's new is quarterly digital reporting — and getting it right could mean your CIS refund lands faster, not slower. (436,000 of 864,000 people mandated this year hit their first deadline on time. Getting your records straight from day one is the difference.)
What actually changes for you
CIS itself isn't changing. Contractors keep deducting tax at source before they pay you. What changes is how you report your income and expenses to HMRC — from one annual Self Assessment return to four quarterly digital updates plus a Final Declaration.
Your qualifying income is your gross CIS turnover — before the CIS deduction, and before expenses
The CIS deduction itself isn't reported quarter by quarter in detail — it's reconciled at your Final Declaration, which is also where any refund gets claimed
If you're a subcontractor working through your own limited company, none of this applies to you yet
If you work for more than one contractor as separate businesses, or also have property income, each needs its own separate quarterly update
The refund angle: many CIS subcontractors have more deducted at source than they actually owe once expenses are accounted for. Keeping accurate digital records through the year tends to mean a cleaner, faster refund at Final Declaration.
Keep your CIS statements straight
Every contractor you work for should give you a monthly Payment and Deduction Statement. These are your primary evidence for both your gross income and the tax already deducted.
Check each statement matches what actually landed in your account
File them digitally as you receive them — monthly, not quarterly
Chase any contractor who's slow to send theirs; you need the figures before your quarterly deadline, not after
Your timeline
NOW
If your 2024/25 income was over £50,000
You've been required to use MTD since 6 April 2026.
6 APR 2027
If your 2025/26 income is over £30,000
You'll be brought in from this date.
6 APR 2028*
If your 2026/27 income is over £20,000
Expected, not yet confirmed in law.
EVERY YEAR
The cycle repeats
Quarterly updates due 7 Aug, 7 Nov, 7 Feb, 7 May. Final Declaration and any refund due 31 January.
Doing it yourself, or through an accountant?
Keep digital records of every CIS statement and expense as you go
Submit four quarterly updates yourself
Reconcile your CIS deductions and claim any refund at your Final Declaration
Nobody else is watching your deadlines for you.
Your accountant needs your CIS statements before they can file — your real deadline is theirs, not HMRC's
Handing over statements as they arrive, rather than in one January bundle, gets your refund back faster
Even with an accountant, you're the one chasing contractors for statements.
What happens if you miss a deadline
One point per missed submission. 4 points = £200, then £200 for every further late submission. No points for late quarterly updates specifically during 2026/27.
Timing
What happens
Days 1–15 late
No penalty
Day 31+ late
3% of the tax owed as of day 15, plus a further 3% as of day 30
Ongoing from day 31
10% a year accruing daily on whatever remains unpaid
Full MTD support kits elsewhere run £15–£30. This is just the dates and reminders — done properly, priced accordingly.
The MTD Deadline Calendar
Every quarterly update and Final Declaration date, 2026/27 through 2028/29
Reminders built in: 3 months, 6 weeks, 2 weeks, 7 days, 3 days and on-the-day nudges before your Final Declaration; a heads-up 10 days and 1 day before each quarterly update
One .ics file — works with iPhone, Google and Outlook calendars
One-off purchase, no account, no subscription
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CIS questions
Does CIS change how much tax I pay?
No. MTD changes reporting, not the CIS deduction rate or how much you ultimately owe.
I work through my own limited company — am I affected?
No. MTD for Income Tax only applies to sole traders and landlords, not limited companies, regardless of CIS status.
What if a contractor is slow sending my statement?
Chase it — you need accurate figures ahead of your own quarterly deadline, which doesn't move to accommodate a late statement.
Will I still get my CIS refund at the end of the year?
Yes, reconciled and claimed through your Final Declaration, same as previously through Self Assessment.