Planned Maintenance

The list below details any planned disruption to services to the best of our knowledge. Disruption to any of these can impact the performance of Sequoia.

This information can change at very short notice. Unless otherwise specified, all times are local.

Last change to the information on this page: Tuesday 05 May 2026 12:36

Service Start time End time Details
ASM Online Services
CCS-UK
CDS Live Service
CDS Test Service (TDR)
12/05/2026 11:00 12/05/2026 15:00 Planned outage on to
See message from the CDS Test Service (TDR)

Good afternoon,

We will be completing a maintenance update to the CDS Trader Dress Rehearsal (TDR) service on Tuesday 12th May.

The outage is expected to last 4 hours, beginning at 12:00 until 16:00. 

During this maintenance window we will be refreshing the below data held in TDR:    

• Trader personal, account, and licensing data, using data which will be copied from Production on Tuesday 12th May.*

*Trader Dress Rehearsal is a sandbox environment and is regularly refreshed with Trader data and data from the Online Tariff on a given date, as such any CDS changes to Trader data in the live service or updates to the Online Tariff will not be reflected in TDR instantaneously.

There will be a complete outage during this period. Please can you inform your contacts. 

Kind regards, 

TDR Communications Team
CNS Compass
ICS2
MCP Destin8
NCTS/CTC
01/06/2026 06:00 01/06/2026 08:00 Planned outage on to
See message from NCTS

We will be carrying out planned maintenance on the New Computerised Transit System (NCTS)

Monday 1st June 2026, 7am to 9am:

•NCTS XI – 7am to 9am
•NCTS GB – 7am to 9am

NCTS GB and NCTS XI data submitted during the period above will be held and processed once the maintenance activity has concluded and the service is available again.

Please see NCTS service availability page to check for latest updates on system availability status.

HMRC apologises for any inconvenience.
Pentant