The CIS monthly-return trap every construction business should know
If you pay subcontractors in construction, HMRC expects a return every month, even in a month you paid no one. Miss it and the penalties stack up quickly. Here is how the CIS monthly return works, and how to stay clear of the fines.
The rule in plain terms
If your business is a contractor under the Construction Industry Scheme, you have to send HMRC a return every single month. The return declares the payments you made to subcontractors, and confirms that the people you paid are genuinely subcontractors rather than employees.
The deadline is the 19th of every month, covering the previous tax month. A return for the tax month running from 6 May to 5 June, for example, is due by 19 June. It is a steady, unforgiving rhythm, and it does not pause when work is quiet.
The nil-return trap
Here is the part that catches businesses out. The obligation to file does not go away in a month when you paid no subcontractors at all. If you made no payments, you still have to tell HMRC, either by sending a nil return that shows your payments were zero, or by asking HMRC to treat you as temporarily inactive.
It is an easy one to miss. A quiet month feels like a month with nothing to do, so the return slips, and a penalty lands for a month in which no money changed hands. That is exactly the situation the nil return exists to prevent.
A quiet month feels like nothing to do, so the return slips, and a penalty lands for a month in which no money changed hands.
What the penalties actually are
The penalties are fixed and they escalate. A return that is one day late brings a £100 penalty. At two months late it is £200. At six months, the penalty rises to £300 or 5% of the deductions on the return, whichever is higher, and the same applies again at twelve months.
Beyond twelve months it gets serious, up to £3,000 or 100% of the deductions, whichever is higher. Because the penalties apply per monthly return, a business that falls behind across several months can find the total climbing fast, even on nil returns where no deductions were due.
What a sensible construction business does
Treat the 19th as a fixed monthly commitment, in the same bracket as payroll, not as an optional task for busy months. Put it in a calendar with a reminder a few days before, and make one named person responsible so it does not fall between people.
If you know you will have no subcontractor payments for a while, tell HMRC and ask to be set as inactive, so you are not filing nil returns you could forget. And keep your subcontractor records, verification numbers and payment details in order, because a clean record is what makes the monthly return quick rather than a scramble.
Where Jamie HR fits, honestly
A straight point first: Jamie HR does not file your CIS returns. Those go through HMRC's CIS online service or your CIS or payroll software, and that is where they should stay. We would rather tell you that plainly than imply a capability we do not have.
What Jamie HR does do is keep the people side of a construction business in order: worker and subcontractor records, documents, and the policies and process behind them, all in one place instead of scattered across spreadsheets and inboxes. When your records are tidy, the monthly compliance jobs, CIS included, are a good deal less painful to feed.