The Deadline Is Closer Than It Looks
If your firm files confirmation statements, handles officer appointments, or manages any Companies House submissions on behalf of clients, there is a compliance step you cannot afford to overlook. From no earlier than November 2026, only firms registered as an Authorised Corporate Service Provider (ACSP) will be permitted to file information at Companies House on behalf of other businesses.
The exact date has not yet been confirmed by Companies House, but the direction is clear and enforcement has already begun. With just weeks of runway remaining before the window closes, now is the time to act.
What Is an ACSP?
An Authorised Corporate Service Provider is a business registered with Companies House under the reforms introduced by the Economic Crime and Corporate Transparency Act 2023. Once registered, an ACSP is permitted to:
- Verify the identity of clients for Companies House purposes
- File statutory documents at Companies House on behalf of clients
- Carry out other authorised activities within the company secretarial workflow
Registration opened to third-party providers on 18 March 2025 and carries a one-off fee of £55. Firms that have already registered are operating under the new regime. Those that have not yet done so are running out of time.
Why This Matters for Accounting Firms
The ACSP regime affects any practice that files documents at Companies House on behalf of clients. This is not limited to specialist company secretarial firms. If your practice handles confirmation statement filings (CS01), officer appointments or resignations, PSC register changes, or registered address updates, you are within scope.
The consequence of missing the deadline is direct: practices that are not registered as ACSPs will be unable to submit these filings for clients. Every UK limited company is required to file a confirmation statement at least once a year. For practices with a company secretarial workload, losing the ability to file is a significant operational and commercial risk.
Enforcement is already underway. HMRC and Companies House have issued 50 suspensions and 27 cease orders against non-compliant filing agents. This is not a soft-launch regime with a generous grace period. Regulatory action is live.
The Identity Verification Piece
ACSP registration is closely linked to the identity verification requirements that became mandatory on November 18th 2025. From that date, all new company directors and persons with significant control (PSCs) must have their identity verified before a filing can proceed. Existing directors and PSCs have until November 18th 2026 to complete verification.
As an ACSP, your firm can verify client identity as part of your own onboarding workflow, rather than directing every individual to the GOV.UK portal separately. This is both more efficient for your team and a better experience for clients. Without ACSP status, you have no route to verify client identity on their behalf at all.
The AML Supervision Link
To register as an ACSP, your firm must be supervised by a recognised Anti-Money Laundering supervisory body. Accepted bodies include ICAEW, ACCA, ICAS, and HMRC's own AML supervision service. This is a hard prerequisite: without current AML supervision, the ACSP application cannot proceed.
This also connects to the mandatory tax adviser registration that came into force in May 2026. A firm that has not resolved its AML supervision status is blocked from both regimes. If AML supervision is not yet in place, that is the starting point for everything else.
It is worth noting that a significant proportion of early ACSP applications were rejected due to data mismatches between firms and their AML supervisory bodies. Applying early gives you time to resolve any discrepancies before the mandatory deadline forces the issue.
Your ACSP Registration Checklist
Here is what your firm needs to do:
- Confirm AML supervision is current. Check your registration with your supervisory body and ensure the information on record is accurate and up to date.
- Verify the identity of key individuals within your practice. Senior role-holders, including directors and partners, must complete identity verification as part of the ACSP registration process.
- Submit your ACSP registration application through the Companies House online portal. The application covers the firm's structure, its senior individuals, and confirmation of AML supervision status.
- Update your client onboarding process. Once registered, your practice can verify client identity as part of onboarding. Build this into your workflow now, before the volume of requests increases closer to the deadline.
- Communicate with clients. Existing directors and PSCs who have not yet verified their identity need to do so by 18 November 2026. Proactive communication now avoids a bottleneck later.
- Set up change notification processes. ACSPs must inform Companies House of any changes to their registered information within 14 days. Assign responsibility for this within your team.
An Opportunity as Well as an Obligation
It is easy to view ACSP registration as another compliance burden in a year that has already brought MTD for Income Tax, mandatory tax adviser registration, and FRS 102 changes. But there is a practical upside.
Firms that register as ACSPs and build identity verification into their onboarding workflow are positioned to offer a more complete service than those that do not. Clients incorporating new companies, appointing new directors, or restructuring ownership need a professional who can manage the full process, including identity verification, without directing them to multiple separate portals. That capability is a differentiator, and it is one that unregistered competitors cannot offer.
The regulatory environment is raising the bar for who can file at Companies House. Firms that clear that bar early are better placed to retain existing clients and attract new ones who need a fully compliant service provider.
Act Now, Not in October
The phrase "plenty of time" has a habit of running out faster than firms expect, and ACSP registration is a good example of why. The application itself is not lengthy, but it depends on other things being in order first: confirmed AML supervision, verified identities for senior individuals, and accurate records held with your supervisory body. Each of those can take longer to resolve than the registration step itself, particularly if a data mismatch surfaces partway through.
Firms that leave this until the final weeks before the deadline are the ones most likely to find a gap between what they assumed was in place and what Companies House actually has on record. Firms that start now have time to fix that gap quietly, rather than discovering it at the worst possible moment, when a client is mid-transaction and needs a filing submitted urgently.
The Bottom Line
ACSP registration is not optional for any practice that files at Companies House on behalf of clients, and the window to sort it out calmly, rather than under pressure, is closing. Confirm your AML supervision status, get senior individuals through identity verification, and submit your application well ahead of the deadline. The firms that treat this as a priority now, rather than a task for later in the year, will be the ones still filing without interruption when the rules take effect.
Managing multiple overlapping compliance deadlines, from MTD to AML to Companies House reform, is easier with practice management tools that give you a clear view across your whole client base. If you would like to see how TaxCalc can help, take a free trial today.
