Relation, authorisation and sequence errorsRelation & missing element

CDS12015Sequence Error: AdditionalMessage.declarationReference does not refer to an existing declaration or the existing declaration is not in a permissible state to process the request

HMRC explanation

Declaration status does not allow request
The request to arrive, amend or cancel declaration is invalid because the declaration cannot be found or is in a state that will not allow the requested action.

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.

A declaration that clears CDS can still be wrong

The free eligibility checker confirms your import activity and whether a free post-clearance audit applies. No data upload, no commitment.

Run a free audit

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