Relation, authorisation and sequence errorsRelation & missing element

CDS12121Relation Error: This combination of Additional Information codes (D.E. 2/2) is not allowed

HMRC explanation

There is an error with the Additional Information codes against a goods item.

Either, the AI codes declared together for one goods item are not compatible with each other, or an AI code entered for the goods item mandates another AI is present.

Source: HMRC, Customs Declaration Service error codes, Open Government Licence v3.0. GOV.UK publication · Licence

What to check across the Relation, authorisation and sequence errors

Two elements, or a value and a rule, disagree. Read both elements together: completing one element with a particular code often requires another value, and the fault is frequently in the element you did not change. The family also covers parties and authorisations that are not recognised, references that must be unique, and messages sent out of sequence.

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Source: HMRC, Customs Declaration Service error codes, Open Government Licence v3.0. GOV.UK publication · Licence