HMRC has published its consultation on timely payments in Income Tax Self Assessment, with the consultation closing on 4 August 2026. The headline proposal was first announced at Budget 2025 and is now being worked through in detail. From April 2029, Self Assessment taxpayers who also have sufficient PAYE income would pay a large share of their Self Assessment liability during the tax year itself, collected through their tax code each payday rather than settled the following January.
That is a structural change to how roughly every side-hustler, landlord and dividend-taking director on your client list experiences tax. The amount owed does not change. The date it leaves their bank account moves forward by up to a year. For a practice, this is the kind of reform that produces a wave of confused inbound questions from people who have no idea it is coming, and a much smaller number of firms who have already answered it in writing.
What HMRC is actually proposing
Under the main proposal, a taxpayer with enough PAYE income would have their Self Assessment liability forecast from their last filed tax return, split into equal amounts, and collected through PAYE across the year. Taxpayers would be able to update the forecast with more recent information, and the deductions would adjust to match.
HMRC has proposed a cap so that no more than 50 percent of PAYE income can be taken in any single pay period, and is asking whether that ceiling needs flexibility. Employers sit in the middle of this. Tax codes would change more often, and employers currently paying PAYE quarterly may be pushed onto monthly payment. The consultation openly asks what extra support employers will need.
A second strand looks at taxpayers who have no PAYE income at all. For them, the government is considering making payments on account more frequent, possibly monthly or quarterly, and bringing them forward so the tax is paid in the same tax year as the income is earned. It is also considering lowering the 1,000 pound threshold at which payments on account start to apply, which would pull a fresh population of small taxpayers into instalments for the first time.
The transition year almost nobody has priced in
The detail that will generate the most client anxiety is 2029-30. In that transitional year, liabilities falling due under the new payment schedule land alongside liabilities still due under the old one. Two systems, one bank account.
HMRC is consulting on ways to soften it, including advance payment options such as a Budget Payment Plan and spreading the previous year's liability over a longer window. One option floated is spreading the July payment on account over four, six or twelve months on top of the in-year 2029-30 payments. None of that removes the underlying problem, which is that a client who has budgeted for one January bill will meet a year where the timing doubles up.
There is a second group with a real problem. HMRC notes that it can currently take up to 22 months before a new trader starts paying tax, and it is asking how newly registered or returning Self Assessment taxpayers should be brought into timely payment when there is no reliable prior-year return to forecast from. Any client who starts trading around the switchover is exposed to a rule that has not been written yet.
What it does to the agent's job
The consultation says plainly that the proposals will add work for tax agents, and gives the example of updating client forecasts as circumstances change in-year. Read that carefully, because it changes the shape of the compliance year.
Today the work is concentrated: gather records, file, tell the client what to pay by 31 January. Under timely payment, the forecast becomes a live number that has to be revisited whenever a client's income moves. That is either an unbilled drag on your team or a productised service with a fee attached. Which of those it becomes depends on decisions your firm makes in the next two years, not in 2029.
The firms already treating HMRC change as a service design question are the same ones who moved early on agent registration with HMRC and on Companies House identity verification. The pattern repeats. The reform arrives with a long lead time, most practices treat it as a 2029 problem, and a small number turn the lead time into positioning.
The opportunity: own the cashflow conversation before HMRC starts it
There is a specific and winnable position here. Almost no UK accounting firm currently has a clear, client-facing page explaining what timely payment means for a landlord with a salary, or a marketing manager with 12,000 pounds of freelance income, or a director drawing dividends. Search demand for this will build steadily from now to 2029, and the pages that exist early are the pages that accumulate authority.
Three things make that page work. First, worked examples with real numbers rather than a summary of the consultation document. Second, a plain answer to the only question the client actually has, which is whether they will pay more overall. They will not, they will pay sooner. Third, a named next step, because a page that ends in a general invitation converts far worse than one that offers a 20-minute cashflow review.
This is also a referral asset. Mortgage brokers, IFAs and property agents all deal with clients whose net monthly income is about to change shape. A firm that gives those introducers something intelligible to forward becomes the firm they forward to.
The opportunity cost of waiting until 2028
The cost of silence is not abstract. It shows up in three places.
You lose the search position. Content that ranks for a reform ranks because it was published early enough to be linked, cited and refreshed. A page published in 2028 competes against pages with two years of history, and against whatever the large national firms have already built. The window where the keyword is cheap is now.
You lose the framing. If a client first hears about this from a news headline about tax being taken from their payslip, your job becomes reassurance and damage control. If they hear it from you, with numbers, your job becomes advice. Same information, completely different position in the relationship.
You lose the fee conversation. Once the forecast maintenance work arrives unannounced in 2029, it gets absorbed into existing fixed fees because there was never a moment to price it. Firms that describe the work publicly before it becomes mandatory are the ones who get to charge for it.
There is a fourth cost, quieter than the others. Clients who feel blindsided by a tax change start shopping. The switching behaviour we see across UK practices tends to spike after a compliance shock, not before it.
Where the visibility work actually sits
Being right about the reform is not the same as being found on it. Three pieces have to be in place.
The search layer comes first. Your explainer needs to be structured so it answers the specific questions people type, not the ones HMRC titles its documents with. Search engine optimisation for a topic like this is mostly about question mapping and internal linking, and both are cheap to do well if done at the point of writing rather than retrofitted.
The site has to convert. A long technical page that ends without a clear route to a conversation is a research library, not a marketing asset. Website design and development work here is unglamorous: readable typography, a visible booking route, and pages that load fast enough that a director reading on a phone at 9pm does not leave.
The list has to hear it first. Your existing clients and introducers are the highest-intent audience you will ever have on this topic, and they should get the explainer before it is promoted anywhere else. Email and lifecycle marketing turns a single page into a sequence: what is changing, what it means for you specifically, and what we are doing about it.
For the wider picture of how these pieces fit together for a practice, our guide to digital marketing for accounting firms sets out the full model, and our UK digital marketing agency page covers how we run it for firms in this market.
What to do in the next 30 days
Start by segmenting. Run a filter for clients with both employment income and Self Assessment income, because those are the people the PAYE strand hits first. Add a second list for clients whose payments on account currently sit just above the 1,000 pound threshold, since a lower threshold would change their position too.
Then write one page, not five. Cover what changes, when, the 50 percent cap, the 2029-30 double-up, and what you are doing about it. Publish it as a page on your site rather than a downloadable PDF, because a PDF cannot rank and cannot be updated cleanly as the consultation response lands.
Finally, put a review date in the diary. The government will publish a response, and the firm that updates its page within a week of that response gets a second wave of attention for the cost of an hour's work.
Triomatic Marketing builds the visibility side of this for accounting firms across the UK and USA. We are AI-powered and founder-led, and we treat a compliance change as what it actually is for a practice, which is a scheduled moment when clients decide whether their adviser is ahead or behind. To talk it through, message Aria on WhatsApp via triomaticmarketing.com, or book a free 15-minute discovery call at https://calendly.com/hello-triomaticmarketing/15min.
FAQs
What is HMRC's timely payments proposal for Self Assessment?
HMRC is consulting on collecting more Income Tax Self Assessment during the tax year itself from April 2029. Taxpayers with sufficient PAYE income would pay a forecast of their Self Assessment liability through their tax code each payday, rather than settling it the following January.
When does the change take effect and when did the consultation close?
The proposed start date is April 2029. The measure was announced at Budget 2025 and HMRC's detailed consultation on how it would work closed on 4 August 2026. A government response is expected before legislation is finalised.
Will clients pay more tax under timely payments?
No. The government's position is that the total liability is unchanged and only the timing moves, so clients pay the same amount earlier and in smaller instalments. The practical impact is on cashflow rather than the tax bill itself.
How much can be taken through PAYE in one pay period?
HMRC has proposed capping the amount collected at 50 percent of PAYE income in any single pay period, and is asking whether that ceiling should be flexible. Employers may also see tax codes change more frequently and quarterly PAYE payers may move to monthly.
What happens to payments on account?
For Self Assessment taxpayers without PAYE income, the government is considering more frequent payments on account from April 2029, possibly monthly or quarterly, paid in the same tax year as the income arises. It is also considering reducing the 1,000 pound threshold at which payments on account apply.
How should a UK accounting firm market itself around this reform?
Publish one clear client-facing page with worked examples, segment clients who have both employment and Self Assessment income, email those clients first, and update the page when the government response is published. Early pages accumulate search authority before demand peaks closer to 2029.