NCTS Downtime is scheduled as follows:

Both Great Britain (GB) and Northern Ireland (XI) services are expected to be unavailable as follows:

Monday 1st June From 07:00 (BST) to 09:00 (BST)

Messages related to Inbound and Outbound movements generated during the scheduled downtime will be queued until the service is restored. Queued messages should then progress as normal. 

Important information about the status of submitted declarations

Departures:

HMRC recommend that all departure declarations submitted before 07:00 BST on 1st June 2026 reach accepted status before the downtime. This will minimise the risk of disruption to the movement.

HMRC have also said they are confident that movements still in submitted status are unlikely to be adversely affected. This assumption is based on system testing and there being little difference between NCTS5 and NCTS6. Declarations submitted in NCTS5 should progress in NCTS6 without difficulty.

Any declarations that are rejected will need to be resubmitted once the system becomes available.

It is also recommended that departure movements under the normal procedure, where the movement requires attendance at an Inland Border Facility, should not be started while the system is down

If goods must be moved during downtime, HMRC requests that the relevant declarations be submitted before 7 am on June 1st when the downtime begins.

The Business Continuity Procedure is available if it is imperative that a movement be started during downtime. However, it is recommended that goods should not travel to an IBF or port to start a transit movement until the system is back online. 

The business continuity processes can be found in the Transit Manual Supplement at the link below:

Transit Manual Supplement.

Arrivals:

Arrivals into GB or XI should continue their movement as usual, although some transit processes, such as the Office of Destination, may need to be completed once NCTS is available again.

Escalations during downtime

Urgent support is available during downtime as follows:

NCTS Helpdesk:  ncts.helpdesk@hmrc.gov.uk

Service level: responses within 5 working days.

NCTS Supervising Office – isbc.nctssupervisingoffice@hmrc.gov.uk 

Service level: responses within 4 hours.

Confirmation of the system going live will be published on the HMRC service availability page.

The HMRC service availability page is available here: service availability 

Important – for users of third-party software

Third-party software providers will update their services to send and receive messages during the same downtime period, using a new API as part of the migration process.

Third-party software providers will confirm when their updated service will be available on 1st June. Do not use the NCTS service until the provider has confirmed that it is ready to use.

A link to the Strong and Herd article with full details of NCTS6 Phase 2 Impact is below:

HMRC Preparation to Implement NCTS6 Phase 2