Key points:
- HMRC’s CDS release 5.3.1.1 goes live on 26 November 2026, without a system outage.
- It adds new document codes, additional information codes and goods location codes.
- Affected pre-lodged declarations for goods arriving on or after 26 November must be amended, or they will be rejected.
What changes on 26 November
The update covers three areas: document codes, additional information (AI) codes and goods location codes, the British International Freight Association (BIFA) told its members. According to the guidance for traders, the main changes are:
- Document code Y388 for steel shipments into Northern Ireland melted and poured in more than one country. The countries, or their codes, must be listed in the document ID field.
- Document code Y501, a second new code added in the latest version of the guidance.
- AI code GMSCK for fresh produce covered by the General Marketing Standards that is selected for examination. These declarations get a “No Match” message through the Border Trade Matching Service and must be amended with GMSCK and document code C085, including the reference of the related plant health document (CHED-PP).
- AI code GRDEF to record due diligence statements for grouped goods covered by the EU Deforestation Regulation from 30 December 2026.
- New goods location codes added to the CDS code list. HMRC says the matching appendix will be updated as soon as possible after the release.
Why loads could get stuck
Many declarations are lodged before the goods arrive, so that trucks can drive straight through the port. That is where the risk lies. A declaration submitted now for goods arriving on or after 26 November follows today’s rules, but it will be checked against the new ones. If it is affected by the changes and not amended, it will be rejected.
The update does not require a system outage, so there will be no break in service on the day. But that also means there is no natural pause in which to catch mistakes: the new validation rules apply from the moment the release goes live.
For a haulier, a rejected declaration means the goods cannot be released until a valid one is submitted, which can mean waiting at the port or in a holding area. The changes matter most for forwarders and customs agents handling steel into Northern Ireland, fresh fruit and vegetables, and goods covered by the deforestation rules.
Hauliers moving goods between Great Britain and Northern Ireland should also make sure their agents are using the new Trader Support Service platform.
What to do now
BIFA recommends that its members:
- read the HMRC guidance for traders on release 5.3.1.1,
- identify all pre-lodged declarations for goods that may arrive on or after 26 November and check them against the new rules,
- update document codes, AI codes and goods location codes in their customs software, or check that their software provider has done so.
The release is one of several customs changes before the end of the year. From 1 January 2027, importers will also have to deal with the UK’s new carbon border tax, which brings its own data requirements.
