Companies House has changed the reference numbering format used within its overnight image-processing service after the existing numeric sequence approached its maximum limit.
From 12 August 2026, affected image references began transitioning from a four-digit numeric sequence to an alphanumeric sequence.
For example:
NIind_con.9999NIind_con.A001Some automated processes may have been configured to accept only four-digit numeric references, which could prevent them from correctly processing images supplied under the new format.
Our data engineering team has updated our systems to support the new alphanumeric references, and the fix is now in place. Companies House images supplied through Doorda will continue to be processed as expected, and no action is required from Doorda customers.
Companies House is also reviewing the long-term numbering approach for Scottish company registrations. No changes have been announced at this stage. We will continue to monitor any future updates and adapt our systems where necessary.