NCTS6 Phase 2: Migration overview

NCTS6 builds on NCTS5 and is mostly about evolving the NCTS transit system to comply with updated EU legal and safety and security requirements. NCTS6 does not introduce a completely new transit process, as was the case with NCTS5. The major goal of NCTS6 is to align the transit system to the Import and Control System 2 (ICS2) where possible.

Review: NCTS6 Phase 1 (opt-in/opt-out countries)

In September 2025 all customs authorities operating NCTS5 had to be compatible with the EU's requirements for NCTS6. The September release, also referred to as NCTS6 Phase 1, included changes to the security codes. The changes depended on whether an NCTS country was an opt-in or opt-out country.

• Opt-in countries: connect ICS2 to NCTS and allow a combined safety and security declaration.
• Opt-out countries: do not connect ICS2 to NCTS and therefore a separate ENS declaration must be submitted alongside a transit declaration. The ENS reference must then be included in the transit declaration.

Belgium, the Netherlands and the UK are all opt-out countries. Each country can decide at any point to become an opt-in country. AEB will communicate any changes around this in advance.

NCTS6  Phase 2

NCTS6 Phase 2 will only introduce minor changes to rules and conditions as well as a few updates to some data groups and elements. The EU has mandated that all countries implement NCTS6 Phase 2 by June 1, 2026 in order to be compliant with the new NCTS legal requirements.

Deadlines

The deadlines for the implementation of the NCTS6 changes are as follows:

• Belgium: Go-live was on April 1, 2026.
• The Netherlands: May 16, 2026
• UK: June 1, 2026. HMRC state that NCTS6 will be down between 7am and 9am on this day.

Note: The changes will be introduced as a big bang and there will be no transition period due to the minimal changes introduced.