Software developer: During the transition period Customs will send response messages in two different versions to import declarations

Import message exchange declarants have a transition period 5 November–31 December 2022, during which updated and new import and customs warehousing declarations will be deployed.

During the transition period, Customs will convert any messages sent by customers in the old format into the new format. Customs will send import and customs warehousing response messages all structured both as the old (A version) and the new (B version), regardless of whether the message sent by the customer was consistent with the old or the new version.

The message declarant’s software must be constructed in such a way that it retrieves both versions of the Customs response message during the transition period. Software developers must ensure that a compatible version of the two is deployed with the software. 

More information:
Software developers: transition period for import declarations and changes to messages
UCC(at)tulli.fi