Compliance
UK Watchdog Probes Companies House Web Filing Lapse

Cybersecurity and other threats raise questions about the extent to which government and private bodies can gather potentially sensitive financial and other information about individuals, creating tensions between privacy on one hand, and calls for transparency, on the other.
The
Information Commissioner’s Office (ICO) in the UK has told
WealthBriefing that it is probing a recent security
lapse at Companies House –
the database used to log details of registered companies in the
country.
On Friday 13 March, Companies House was made aware of a security
issue which meant that a logged-in user of its WebFiling service
could potentially access and change some elements of another
company’s details without their consent after performing a
specific set of actions, the organisation said in a 16 March
statement.
The incident came at a time when cybersecurity threats pose a
challenge to public bodies responsible for guarding details
of business owners and taxpayers. It also casts light on the
scope of GDPR regulations and the ways they can apply differently
to private and state sector organisations.
"We can confirm we have contacted Companies House and are
assessing the information provided,” a spokesperson for ICO told
this news service when asked about the matter on 23 March. The
ICO did not elaborate.
The UK government must act severely to show it takes such matters
seriously, Filippo Noseda, partner at Mishcon de Reya,
said on his LinkedIn page. Noseda has also talked to this news
service regularly about the potential collision between data
protection requirements and government collection of data on
individuals’ financial lives.
“Unless the ICO intervenes with full force, it will be indicative
of the failure of UK government in the field of data protection
in the UK,” Noseda said.
Noseda said he has filed a GDPR compliant with the ICO. “I'm not
holding my breath, as the ICO has effectively abdicated its
regulatory mission when it comes to governments. However, another
example of ICO inaction would expose the moribund state of data
protection in the UK, so it's a cause worth pursuing.”
In its statement, the ICO said it had closed WebFiling at 1:30pm
on Friday 13 March while it investigated and resolved the issue.
The service was independently tested and returned online from
9:00 am on Monday 16 March.
“Our investigation has established that specific data from
individual companies not normally published on the Companies
House register may have been visible to other logged-in WebFiling
users. This includes dates of birth, residential addresses and
company email addresses. It may also have been possible for
unauthorised filings – such as accounts or changes of
director – to have been made on another company’s record,”
it said.
Companies House said that passwords were not compromised; no data
used as part of its identity verification process, such as
passport information, was accessed, and no existing filed
documents, such as accounts or confirmation statements, could
have been altered.
“We believe that this issue could not have been used to extract
data in large volumes or to access records systematically. Any
access would have been limited to individual company records,
viewed one at a time by a registered WebFiling user,” it
said.
The organisation said the breach happened when it updated
WebFiling systems in October 2025.
Companies House said it “proactively reported this incident to
the Information Commissioner’s Office (ICO) and the National
Cyber Security Centre (NCSC)”.
The organisation did not describe the incident as a data breach,
typically defined as "the unauthorized exposure, disclosure, or
loss of personal information."
Public bodies around the world have been affected by incidents,
some dramatic, as in the case that took place from 2018
through 2020, when Charles Littlejohn stole tax return
information for thousands of high net worth persons and related
entities and disclosed it to ProPublica and other entities. In
April 2024, the Internal
Revenue Service began notifying thousands of taxpayers that
their tax return information was subject to a data breach.