As a result of these legislative changes, Companies House can now actively query, investigate, and reject filings, demanding supporting evidence when information appears incorrect. This article explains how the GOV.UK One Login migration works, and its implications on the Companies House authentication code, identity verification and ACSP registration requirements, and outlines precisely what these comprehensive transparency reforms mean for company directors and accountants.
- From 13 October 2025, shared access to the Companies House WebFiling account will no longer be an option.
- Create an individual GOV.UK One Login using a unique email address for every person who files company documents, including directors, accountants, and authorised officers.
- Linking a legacy WebFiling account to a single GOV.UK One Login immediately revokes access for all previously shared users.
- Keep the company’s existing authentication code, as this remains the essential proof of your authority to access online services and file documents through your new individual Login.
What does Companies House WebFiling do?
Companies House WebFiling service is the free online filing portal that enables the digital filing of most statutory documents for limited companies and LLPs. It is used for routine company secretarial tasks, such as submitting confirmation statements, annual accounts, share allotments, and changing company details, such as registered office addresses. The service processes forms within approximately 24 hours, making it significantly faster and cheaper than paper methods.
However, the WebFiling service’s access point has fundamentally changed, even though the underlying filing platform remains. Companies must now access this service exclusively through the GOV.UK One Login system.
Yet, even with the migration, you will still be unable to access WebFiling through the new GOV.UK One Login if your company number falls under specific exclusion criteria. This restriction applies if your company number contains only digits or if it uses the following geographical prefixes:
- Limited Companies: NI, RO, or SC
- Limited Liability Partnerships (LLPs): OC, SO, or NC
Additionally, companies with 1,000 or more shareholders, those requiring subsidiary undertaking lists, or those with complex share structures exceeding specific thresholds cannot use webfiling.
How Your Company Authentication Code Works (And Why It’s Not Going Away)
A company authentication code serves as its digital signature for online filing. This 6-digit alphanumeric code, containing numbers and letters, authorises you to file information with Companies House. Without this code, online filing is impossible.
Whenever a new company is incorporated, the code is sent by post to your company’s registered office address within 5 working days, though delivery may take up to 10 working days during peak periods. The code is never sent by email, but can be sent to the home address of an active director if requested
If you lose your code, the process for receiving a new code remains the same. Sign in to Companies House WebFiling and select your company. Choose “Request a new authentication code” and confirm your company registration number. The code will be sent to your company address or the home address of an active director.
The migration to GOV.UK One Login introduces a new security setup that includes your One Login credentials, two-factor authentication, and company-specific authentication codes. Previously, each authentication code was tied to a shared WebFiling account. Under the new system, every authentication code is linked to an individual’s GOV.UK One Login. Now, to file on behalf of a company, you must use that company’s unique authentication code through your personal One Login portal.
If you formed your company through your company formations, we will normally have an online manager facility that displays the code immediately after incorporation.
GOV.UK One Login Replaces Shared WebFiling Accounts from 13 October 2025
GOV.UK One Login is a unified platform for accessing all UK government services, including Government Gateway and webfiling. The online services platform offers single sign-on with a single username and password, mandatory two-factor authentication via text message or authenticator apps, and optional identity verification.
From 13 October 2025, you must connect your webfiling account to GOV.UK One Login to access webfiling. Afterwards, if you try to sign in to Companies House webfiling from 13 October onwards, the system redirects you to connect your account to GOV.UK One Login.
Users with existing GOV.UK One Login accounts sign in and connect immediately. Those without accounts receive prompts to create an account during the connection process.
Only one person can connect each webfiling account to their GOV.UK One Login, you can’t share your webfiling account with others anymore. Previously, accounting firms, company formation agencies, and corporate teams routinely shared single webfiling accounts. Multiple staff members accessed the same account to file for numerous client companies. From 13 October 2025, shared accounts became technically impossible.
Each team member now needs their own GOV.UK One Login account with a unique email address. Each will also require separate authorisation (using webfiling authentication codes) for every company they file for. You can’t use the same email address for multiple GOV.UK One Login accounts.
To create their own GOV.UK One Login, team members visit the sign-in page and select “create an account.” The process requires a unique email address, password creation, and setting up two-factor authentication via text message or an authenticator app. Once created, users must connect their new webfiling account to their personal GOV.UK One Login.
Under GOV.UK One Login, one person connects to that original account, while the other four team members lose access to the filing history and company information. Each of those four people must create an account, establish new webfiling profiles, and obtain authorisation—requiring authentication codes—for each client company they serve.
The practice must now manage five separate webfiling accounts across team members and track which individuals hold authorisation for which clients. Company authentication codes become critically important as the mechanism for granting individual authorisations. Without proper code management, team members can’t file for clients.
You have five staff members serving 10 clients. One person connects the original webfiling account that contains all historical company details and filing history. The other four lose access to that information completely unless you recreate their access individually.
Each of those four people must:
- Create their own GOV.UK One Login using a unique email address
- Set up a new webfiling account
- Request authentication codes for each of the 200 companies (or whichever subset they manage)
- Wait five working days for each authentication code to arrive by post
- Enter each code to be able to access WebFiling for that specific company
You’re now managing five separate webfiling accounts instead of one shared account. You need systems to track which team member holds authorisation for which clients. Your authentication code management becomes a strategic operational capability rather than an administrative afterthought.
Identity Verification Became Mandatory on 18 November 2025
Separately from One Login’s optional identity check, ECCTA made identity verification mandatory from 18 November 2025. Anyone setting up, running or controlling a company must now verify their identity, either directly through GOV.UK One Login or via an Authorised Corporate Service Provider (ACSP). New directors and PSCs verify before appointment. Existing directors verify when they file their next confirmation statement, so most will complete this during the transition year running to November 2026.
How the WebFiling Migration Affects Accountants and Bookkeepers
Accountants and bookkeepers who file information for multiple client companies face greater administrative effort. Shared WebFiling accounts are no longer permitted. Each person who files must now have their own GOV.UK One Login and separate authorisation using each company’s authentication code.
Company Formation Agents
Company formation agents face similar restructuring. Previously, one shared account could manage hundreds of client companies. Now, every team member who files company information must have individual access.
The challenge increases because new companies are constantly being created. When you form a company for a client, you receive its authentication code. You must now distribute that code to the appropriate team members and track who holds authorisation for each client. This change necessitates a comprehensive overhaul of your client handover and access management processes.
Formation agents who already store authentication codes in secure client portals have an advantage, as clients can retrieve their codes directly. However, each team member still needs their own GOV.UK One Login and individual authorisation for the companies they manage.
Company Secretarial Teams
Internal company secretaries managing subsidiaries or group structures must determine which employees need access to file documents. Each authorised person must have a unique email address to create their GOV.UK One Login. You will also need to coordinate individual authorisations using authentication codes across your entire company portfolio.
Large groups with multiple subsidiaries must request authentication codes for each entity and distribute them to authorised staff. The days of a shared login for the secretarial department officially ended on 13 October 2025.
Software Users
Users of third-party software for filing still need WebFiling accounts with presenter IDs. These accounts must also be connected to GOV.UK One Login. The integration between software and Companies House remains active, but access control now applies at the individual account level.
Identity Verification and ACSP Registration: Two More Changes Coming Soon
The migration to GOV.UK One Login marks only the first stage of authentication reform. Two additional requirements, identity verification and Authorised Corporate Service Provider (ACSP) registration, take effect between late 2025 and early 2026.
From 18 November 2025, all company directors and people with significant control (PSCs) must verify their identity with Companies House. New directors must do so within 14 days of appointment or incorporation. Existing directors and PSCs will receive 14-day verification windows during a rolling 12-month transition period.
After verification, Companies House issues an 11-character personal code distinct from your company authentication code and GOV.UK One Login credentials. This individual code is required when submitting filings that need verified identity confirmation.
ACSP registration becomes mandatory for accountants, company formation agents, and anyone filing on behalf of others. The registration service opened for voluntary enrolment on 18 March 2025 and became compulsory from Spring 2026. Filing for clients without ACSP status will be illegal under company law.
The registration fee is £55, paid once, and registrants must remain under supervision by UK Anti-Money Laundering regulatory bodies. From 8 April 2025, ACSPs can also provide identity verification services to clients, offering a potential new revenue stream.
This reform formalises the role of professional intermediaries and introduces direct oversight. Smaller practices that occasionally file company documents may find the compliance burden outweighs the benefits and could withdraw from the market.
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