Companies House has confirmed that a package of accounts filing reforms under the Economic Crime and Corporate Transparency Act 2023 (ECCTA) will come into force from 1 April 2028, changing how every UK-registered company files its annual accounts.

At a glance

• Small companies and micro-entities will be required to file profit and loss (P&L) accounts with Companies House, in line with other companies, and the option to file abridged accounts is removed.
• All companies must file accounts in iXBRL format using commercial software; the Companies House web-filing and paper filing routes for accounts will close.
• The implementation date has moved from April 2027 to April 2028, giving companies one full accounting year plus nine months (21 months) to prepare.

The reforms affect every UK company but land hardest on small companies and micro-entities, which have until now had a lighter reporting burden.

Background

The accounts reforms sit within the wider ECCTA programme aimed at improving the transparency and reliability of data on the companies register. For years, small companies and micro-entities have filed abbreviated or abridged accounts that revealed little about their financial performance. That offered privacy, but left Companies House with limited visibility over the financial health of a large share of UK companies. The implementation timetable was pushed back specifically to give companies more time to transition.

What Is Changing

• Mandatory P&L accounts for small companies and micro-entities: These companies must now file a P&L account with Companies House, as larger companies already do, and the option to file abridged accounts disappears entirely. They may opt out of publishing the P&L on the public register, but Companies House, law enforcement, and HMRC will still see it, and the opt-out mechanism itself hasn’t been detailed yet.
• Software-only filing: All UK companies, whether filing directly or through an agent or accountant, must use commercial software in iXBRL format. From April 2028 the web and paper filing routes close for good.
• Strengthened audit exemption statement: Companies claiming an audit exemption face a tighter eligibility statement requirement.
• Filing mechanics tightened: All parts of the accounts and reports must be filed together, and companies get fewer chances to shorten their accounting reference period.

Impact and Practical Steps

Small companies and micro-entities lose their lighter-touch regime and must prepare a full P&L, with the privacy trade-off depending on an opt-out mechanism that’s still being worked out. Separately, any company still filing via web or paper must transition to iXBRL-compatible commercial software before the deadline.  Practical steps include confirming whether the company qualifies as a small company or micro-entity, checking the company authentication code is available, applying for a presenter account if needed, and confirming any accountant’s software will meet the new requirement.

Timeline

The reforms take effect 1 April 2028, postponed from the original April 2027 date, giving companies roughly 21 months to prepare.