Relation, authorisation and sequence errorsRelation & missing element

CDS12105Relation error: Addition/Deduction code (DE 4/9) not allowed with the declared Additional Procedure Code (DE1/11)

HMRC explanation

Relation error
When using additional procedure code E01 (simplified procedure value) or E02 (standard import value), data element 4/9 additions and deductions, must not be declared. See Appendix 1 for more information.

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