Companies House Confirmed Software-Only Filing for 2028, and Every Small Company Client Is Affected

Companies House confirmed in June 2026 the start date for the largest package of accounts filing reforms it has ever introduced: April 2028. From that date, every UK registered company must file its annual accounts through commercial software in iXBRL format, the web and paper filing routes close for accounts entirely, and small companies and micro-entities must file a profit and loss account for the first time. The confirmation, published on GOV.UK and analysed by ICAEW and AccountingWEB within days, ends months of speculation about whether the Economic Crime and Corporate Transparency Act accounts reforms would be paused, diluted or quietly dropped. They were not. They now have a date.

The package was originally expected in April 2027. The confirmed April 2028 start gives companies one full accounting year plus nine months to adjust, roughly 21 months of runway from the announcement. For a single company that is comfortable. For an accounting firm with two or three hundred small company clients, every one of whom needs a filing-software decision, a disclosure conversation and possibly a revised engagement letter, it is a rolling project that needs to start well before the deadline year.

What actually changes in April 2028

Software-only filing is the headline. Companies House will accept accounts only in iXBRL format produced by commercial software. The web filing service and paper filing close for accounts completely. Any client who currently types their numbers into the Companies House website once a year, and a meaningful share of unrepresented small companies do exactly that, loses that route. They will either buy software and learn it, or appoint an agent who files for them.

Small companies and micro-entities must file a profit and loss account. This is the change directors will actually feel. Under the new rules they must deliver a profit and loss account to Companies House, with an option to keep it off the public register. Filing becomes mandatory; publication remains a choice. That distinction, and what it means in practice, is going to generate more anxious client questions than any other line in the announcement.

Several supporting changes land in the same package. The option to file abridged accounts is removed altogether. Companies claiming an audit exemption will need a strengthened eligibility statement from directors identifying the specific exemption relied on. The component parts of accounts and reports must be filed together, and companies lose some of their freedom to repeatedly shorten their accounting reference period, a tactic that has been used to delay filings indefinitely.

Why this is an advisory event, not an IT upgrade

The instinct inside many firms will be to treat April 2028 as a software procurement question and park it. That reading misses where the value sits. For every small company client this change opens three conversations, and each of them belongs to the accountant rather than the software vendor.

The first is the filing conversation: which product files for this company, who presses the button, and what it costs. Firms that already file on behalf of clients become the default answer to a question hundreds of thousands of companies are about to ask for the first time.

The second is the disclosure conversation, and it carries the emotion. Owner-managers who have never shown turnover or margin to the public register want to know exactly what will be visible, to whom, and what a competitor, customer, landlord or lender could infer from it. Walking a director through the profit and loss opt-out, what it covers, what it does not, and filing it correctly is precisely the kind of judgement a software subscription cannot supply.

The disclosure decision deserves its own framework, because directors will ask who actually reads the register. The honest answer: competitors benchmarking margins, suppliers and landlords assessing covenant strength, credit insurers setting limits, journalists, and increasingly the data companies that resell register information in bulk. For some clients the opt-out is obvious. For others, a business courting investment or tendering for contracts, a visible, healthy profit and loss can work in their favour. That judgement call, client by client, is advisory work in its purest form, and it recurs every year.

The third is the audit exemption conversation. A strengthened eligibility statement signed by directors raises the stakes of getting the exemption analysis right, and directors will want their accountant's name next to that analysis before they sign it.

Each of those conversations is a legitimate fee event: a client briefing letter, a disclosure review, a software migration project, an updated engagement. Multiply by the size of the client list and April 2028 starts to look like MTD did in 2019, a compliance change that quietly became a revenue line for the firms that moved early.

The client-acquisition population nobody is naming

There is also a defined group of future clients hiding inside this reform: companies with no accountant that file their own accounts through the web service. From April 2028 their door closes. Some will buy software. Many will decide that the moment has come to hire a firm. Those directors will not ring around; they will search, and they will ask AI assistants questions like whether their profit will become public and how to file accounts once the web service shuts. The firms whose explainers rank for those questions will meet these companies at the exact moment they need help. We described the same dynamic around Companies House identity verification: a deadline-driven change turns quiet directors into active searchers, briefly, and then the window closes.

The cost of waiting until 2027

Twenty-one months sounds like time to spare. It is not, because decisions will not wait for March 2028. Software and adviser choices get made at accounting-year boundaries, which means many clients will effectively decide during their 2026-27 accounts cycle. Vendors know this and are already marketing against the deadline.

The opportunity cost of staying quiet is concrete. Your clients will hear about April 2028 regardless, from software companies, from the trade press, from Companies House itself. The only open question is whether the explanation arrives with your firm's name on it. When a director learns about a major filing change from anyone other than their accountant, the relationship takes a small knock. Enough small knocks and that client drifts into the switching window we wrote about earlier this year, where a more visible firm is waiting with answers already published.

And silence costs the inflow too. The unrepresented companies forced off the web route are going somewhere. If your firm is invisible when they search, they become someone else's growth statistic.

Visibility is the half most firms skip

Advisory capacity means nothing if nobody outside the client list knows it exists. The firms that will win this window are publishing now: a short, precise explainer answering the questions directors are typing, whether profits become public, whether self-filing survives, what iXBRL means, what it will cost. Structured properly, with clear headings and FAQ schema, that page earns search traffic for the full two-year runway and gets quoted by the AI assistants directors increasingly ask first.

That is the core of what we build for accounting firms: SEO that ranks the explainer for the questions being searched, a website that converts the reader into a booked call, and conversion optimisation that turns rising traffic into rising enquiries rather than a vanity chart. The full method is in our guide to digital marketing for accounting firms and the 2026 playbook for UK firms. If you would rather have it done for you, that is what our UK digital marketing team does all day.

What to do before September

Three moves this quarter. First, segment the client base: who files through the web route today, which clients are small or micro and face the profit and loss question, who claims an audit exemption. That list is your campaign audience and your fee forecast in one spreadsheet. Second, send a plain-English briefing to every affected client, four paragraphs, no jargon, ending with an offer of a fifteen-minute call. Third, publish the public version of that briefing as an explainer page on your site, with an FAQ block, so the directors you do not yet act for can find you.

Then put the milestones in the diary. Clients whose 2026-27 accounts you prepare next year will make their software and disclosure decisions during that cycle, which makes spring and summer 2027 the natural moment for the individual conversations, and this autumn the deadline for the firm-wide briefing and the published explainer. Work backwards from April 2028 and the comfortable-sounding runway resolves into about three usable windows. The first one is now.

The firms that turned MTD into growth were not the ones with the best software. They were the ones that explained the change first and were easiest to find while everyone else stayed quiet. April 2028 is the same exam with a longer revision period. Message Aria on WhatsApp at triomaticmarketing.com or book a free 15-minute discovery call and we will map the campaign for your firm before the window gets crowded.

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