On CIS, not sure what you are on about to be honest, CIS income has always been reported as gross whether it be quarterly for VAT or annually for the end of year, the point I was making upthread is why should a Subbie maybe earning as little as £25k a year have to be part of this MTD rubbish when as far as they are concerned they are already having tax deducted.
The ‘only end of year matters’ point is perfectly valid as everything that went before it with the quarterly updates are basically meaningless, as far as I am aware the only penalties starting for the 2027/2028 tax year are for late filing of the quarterly updates, so you can file whatever figures you like as long as the end of year return which determines your tax liability is correct and submitted on time.
So this whole MTD fiasco is a total waste of time which is costing the tax payer more money and time, for absolutely nothing in return.
Fair enough on CIS, you clearly know it's reported gross and I was explaining something you didn't need explaining. And you're right on the penalties, more right than I gave you credit for. HMRC's own wording is "there are no penalties for missing a quarterly update deadline for the 2026 to 2027 tax year," so points don't start until the 2027/28 updates. On accuracy, the professional view is that inaccuracy penalties don't reach quarterly updates at all. Schedule 24 FA 2007 lists the documents it bites on and quarterly updates aren't among them, and they don't meet the catch-all either because HMRC can't determine liability from an update without further inquiry. ATT say it in terms. HMRC themselves say no accounting or tax adjustments are needed, and because updates are cumulative year to date a wrong Q1 figure is cured by the corrected Q2 figure without amending anything.
So on the narrow point, you're right and I'm not going to pretend otherwise. Where I'd still push back is "file whatever figures you like," because there's a separate obligation sitting underneath it that nobody talks about. The digital records requirement is its own duty, in its own regulations, and HMRC's manual puts the penalty for failing it at up to £3,000. That has nothing to do with whether the return is right. If "whatever you like" means submitting the software's rough unadjusted output, fine, that's exactly what it's designed for. If it means not keeping the underlying records and typing a number in, that's the bit that's chargeable. There's also a positive duty to correct an error in your records as soon as you find it, not at the year end.
And a timing thing worth knowing if you've got subbies at £25k. That easement is written against the 2026/27 tax year, not against your first year in MTD. So the £30k lot in April 2027 and the £20k lot in 2028 shouldn't assume they get the same free run. Late payment is the other way round, that easement is framed as your first year in the new system, so it should follow them.
On the wider point, you won't get much of an argument from me. A subbie on £25k who's had tax deducted at source all year, filing five times to arrive at a number HMRC could work out themselves, is the least defensible bit of it. The professional bodies have said much the same about the burden at the small end. It's here regardless, which is the only reason I bother explaining it.