The ZIP file below contains the complete A2C Specification for 2022. Note that the current AO production systems conform to the 2021 spec. The 2022 spec will be effective from 1st September 2022

This does not affect the A2C Transport Application.

If you are a centre with a commercial MIS system your supplier will be implementing A2C and will notify you when an upgrade is available. Only centres with their own “homegrown” systems need to implement A2C themselves.

This copy of the spec contains Adobe Acrobat and Microsoft Excel files, with no change tracking.

If you are actively developing software for A2C it is strongly recommended that you obtain access to the A2C sharepoint site. This contains much supplementary information such as Best Practice, xml examples, AO specific details, etc. It also contains Word versions of the spec with tracked changes from the previous version. To obtain access please email

The A2C Entity Blocks Schema (xsd) is published separately from the spec and is available from the A2C sharepoint site.




Microsoft Word