From April 2028 every company files its accounts at Companies House in iXBRL format using commercial software. The web and paper services close for accounts. Submit builds the iXBRL accounts and files them.
What changes
GOV.UK gives the change below. The notice is dated 23 October 2026.
from April 2028, we will require all UK registered companies to file their accounts in Inline eXtensible Business Reporting Language (iXBRL) format using commercial software.
From this date, our web and paper-based filing systems will be closed for accounts filings.
What stays
Companies House keeps its web service for filings that are not accounts.
Companies House web filing services will remain available and fully supported for non-accounts filings, including confirmation statements and updates to director details.
What Submit files
Submit turns the figures you give it into iXBRL accounts. See micro-entity accounts and small company accounts.
Every date for a company is on the MTD calendar.
Submit files annual accounts at Companies House.
Which date applies
Earlier plans gave a date in 2027. This page follows the GOV.UK notice above, read on the date shown with its quote. Check that page for the current date.