Guidance on preference codes and origin data for tariff measure derivation under Data Elements 5/15 and 5/16

The guidance below relates to preference codes and origin data for tariff measure derivation under Data Elements 5/15 and 5/16 following the implementation of CDS Release 5.1.0 on 28th March 2026. 

As part of Customs Declaration Service (CDS) Release 5.1.0, HMRC is improving how CDS validates preference codes and origin data for tariff measure derivation under Data Elements 5/15 (Country of Origin) and 5/16 (Country of Preferential Origin). 

These changes make CDS better at deciding the correct preferential and nonpreferential tariff measures, ensuring accuracy and reliability when using the country of origin data declared.

What traders need to do

a. Continue to provide the standard Country of Origin code

Use of Country of Origin (DE 5/15):

• traders must continue to declare the standard two-digit ISO country code. 
• do not use new country-group codes, expanded formats, or four-digit codes as they will not be accepted or required.

b. Ensure preferential codes are used correctly

The existing rules remain unchanged:

• preference codes not beginning with ‘1’ → Preferential treatment is being claimed.
• preference codes beginning with ‘1’ → No preferential treatment.

Use of Country of Preferential Origin (DE 5/16):

• • DE 5/16 must be completed when a preferential tariff claim is being made, to support validation of the claimed preference. 
• • where no preferential treatment is claimed (i.e. a 100 series preference code applies), DE 5/16 is not required for GB declarations, as tariff measures will be derived solely from DE 5/15.

CDS will use the combination of preference code, DE 5/15, and (where applicable) DE 5/16 to determine the correct tariff measures.

c. Northern Ireland (NI) – important clarification on DE 5/16

For Northern Ireland declarations, additional rules apply:

• Where: 
• DE 4/17 contains a UK preference code in the 100 series (no UK preferential treatment claimed), and
• an NI/EU preference code is declared against DE 2/2 AI code EUPRF which is not in the 100 series.

• DE 5/16 must be completed to support validation of the NI/EU preferential claim.

If DE 5/16 is excluded in these scenarios, the declaration will be rejected. This happens because the CDS requires DE 5/16 to validate any NI/EU preference claims.

d. Ensure origin evidence is retained and aligns with claims

If preferential treatment is being claimed, traders must continue to hold valid origin evidence to support the declaration, in line with current policy and compliance requirements.

e. Check your declarations for accuracy and amend pre-lodged declarations where required

As a result of improved CDS validation:

• declarations with mismatched preference codes and origin data may now be rejected, where they may previously have passed.
• traders and declarants should review and update their existing data – This includes submitting amendments after the R5.1.0 release, for any pre-lodged declarations that were submitted before the release which will no longer comply with these new requirements when those declarations are arrived. They should ensure correct and consistent usage of DE 5/15, DE 5/16, and preference codes, especially for movements involving NI.

When will the change happen?

This change will be delivered as part of CDS Release 5.1.0 on Saturday 28 March.