HMRC Updates Guidance, SIC Codes Get Teeth, and the Legal Services Incorporation Slump Arrives Right on Cue

1 July 2026. Three HMRC guidance documents updated. One Companies House SIC enforcement blog already weeks old but newly relevant. And, as of the start of Q3, precisely zero new companies incorporated under SIC 69.10 (legal activities) according to AIBD's analysis of Companies House data. Professionals who enjoy a quiet summer are about to find that the regulatory calendar does not share that preference.

What HMRC Actually Updated

The Small Practitioners Association flagged this week that HMRC has quietly refreshed guidance across three areas that accountants encounter on a near-daily basis: reply time estimates, genuine contact verification, and withholding tax on payments to non-UK resident entertainers and sportspersons. The updates are not headline-grabbing. They are, however, the kind of thing that becomes a problem the moment a client asks why their query is taking four months and you cannot point them to the current waiting-time tool.

On reply times: HMRC maintains an online tool that lets agents and taxpayers check expected turnaround on specific query types. The guidance has been updated to reflect current processing realities. Given that many practitioners continue to experience delays when dealing with HMRC, and clients may not always appreciate that the delay is outside the accountant's control, having this resource bookmarked is not optional. It is self-defence.

The genuine contact guidance matters more than it sounds. HMRC sometimes uses more than one communication method: a letter, followed by phone, email, or text. The updated guidance helps distinguish legitimate contact from the phishing attempts that have become structurally indistinguishable from real HMRC correspondence. Clients should be encouraged to check before responding to any unexpected requests for information, payments, or bank details. Telling them after they have handed over their login credentials is, unfortunately, too late to be useful.

The withholding tax update is the narrow one. It applies to clients making payments connected with UK appearances by non-UK resident entertainers and sportspersons, covering events, festivals, sport, entertainment, TV, radio, modelling, promotional appearances, and speaking engagements. HMRC guidance states that if someone who does not live in the UK is paid for making an appearance or performing in the UK, tax must be deducted where the total payment exceeds the personal allowance threshold. Niche, yes. But festival season is upon us, and the number of firms caught flat-footed by this is, historically, embarrassing.

The SIC Code Problem Has Not Gone Away

In May, Companies House's Compliance and Enforcement Service published a reminder that a company's standard industrial classification code must accurately reflect its business activity. This is not new law. It is, however, newly enforced posture, consistent with the broader shift under the Economic Crime and Corporate Transparency Act 2023, which repositioned the registrar from passive filing clerk to active gatekeeper with powers to query, reject, or remove information from the register where there are concerns about accuracy or legitimacy.

The timing is instructive. AIBD's analysis of Companies House data shows zero new incorporations under SIC 69.10 in Q3 2026 to date, a 100% decline against the prior period. This does not necessarily mean solicitors have stopped practising. It almost certainly means that the combination of Authorised Corporate Service Provider requirements, heightened identity verification obligations, and general ECCTA friction has made the casual, speculative incorporation significantly less attractive. When compliance has a cost, people incorporate less casually. The register gets marginally cleaner. Companies House would probably call this a feature.

For firms advising clients on new structures, the practical implication is blunt: if the SIC code on incorporation does not accurately reflect the proposed activity, and the business subsequently draws scrutiny for any other reason, the inaccurate code becomes an additional liability. It is the sort of thing that looks like a small error in year one and a pattern of conduct in year three.

The ACSP Requirement: Still Coming, Still Delayed, Still Your Problem

Third-party agents who file documents at Companies House must be registered as Authorised Corporate Service Providers. This was originally envisaged for spring 2026. Companies House's updated ECCTA transition plan moved the mandatory date to no earlier than November 2026. If your firm files on behalf of clients and has not yet begun the ACSP registration process on the grounds that the deadline keeps shifting, consider this: the November 2026 date is not being shifted to accommodate firms that chose to wait. It is a planning date. The process takes time. Accountants who need to register as ACSPs to submit files or undertake other activities on behalf of clients should not be waiting for a third delay before opening the application.

Identity verification enforcement is also moving from the education-and-engagement phase toward something with more edges. Companies House anticipates commencing compliance activity against those who have failed to complete identity verification in the latter part of 2026. For directors and PSCs who have not yet verified, the personal exposure is real: continuing to act without completing identity verification is an offence under section 167M of the Companies Act 2006, and the company itself is simultaneously in breach for failing to rectify it.

What This Means for Your Monday Morning

Three tasks, ordered by urgency.

First, update your bookmarks. The HMRC reply-time tool, the genuine-contact guidance, and the withholding-tax guidance have all been refreshed. Your client-facing communications should reference the current versions, not whatever you last pointed someone to in 2025.

Second, run the SIC code check across your incorporation client base. If any company's stated SIC code does not match what the business actually does, and in a post-ECCTA world Companies House will eventually ask, now is the moment to file the correction. Not the moment you are trying to close a deal or satisfy a due-diligence request.

Third, check your firm's ACSP registration status. If you file at Companies House on behalf of clients and you are not registered, the window to do it without operational disruption is measured in weeks, not months.

On the Horizon

The Self Assessment paper filing deadline lands on 31 October 2026, a date that will, as it does every year, arrive as a surprise to at least a third of the affected population. The online deadline follows on 31 January 2027. Neither date has moved. Neither will. Plan accordingly.