Cross-border developments and trading corner – 18 May 2026

In this week’s cross-border trading corner, we bring you the latest guidance updates and publications. The most recent Trader Support Service bulletin is also available as is the latest Brexit and Beyond newsletter from the Northern Ireland Assembly EU Affairs team. Earlier this month the European Commission and the UK Government’s Specialised Committee on the Implementation of the Windsor Framework met in Brussels after which a Joint Statement was issued and HMRC has advised that phase six of the New Computerised Transit System (NCTS6) is scheduled for deployment on Monday 1 June 2026.

NCTS 6 deployment update

To support the deployment of NCTS phase six, Great Britain and Northern Ireland services will be unavailable between 7am and 9am on 1 June. HMRC’s guidance sets out the procedures to be followed during NCTS downtime. 

Miscellaneous guidance updates and publications

This week’s miscellaneous guidance updates and publications are as follows:

• Appendix 1: DE 1/10: Requested and Previous Procedure Codes of the Customs Declaration Service (CDS),
• Customs declarants and declaration volumes for international trade in goods,
• Data tables for customs declarants and declaration volumes for international trade in 2025,
• Customs declarants and declaration volumes for international trade in 2025,
• CDS Declaration Completion Instructions for Imports,
• Data Element 2/3: Documents and Other Reference Codes (National) of the Customs Declaration Service (CDS),
• UK import trade in goods by country of origin and country of dispatch, 2024, and
• External temporary storage facilities codes for Data Element 5/23 of the Customs Declaration Service.