HMRC have announced upcoming downtime for the CDS service:
"Due to scheduled maintenance the Customs Declaration Service (CDS) will be unavailable to all users from 8 pm Saturday 28th March 2026 until 5:45 am on Sunday 29th March 2026.
This release is being carried out during British Summer Time (BST) clock change
Declarations should not be submitted during the outage period.
Creating, updating, or embarking a goods movement reference (GMR) during this time might be affected.
Only goods with pre-lodged declarations attached to a GMR will be allowed to move using Goods Vehicle Movement Service (GVMS).
For guidance on GVMS, read GVMS Service Availability and Issues.
For import movements using GVMS, you should check the declaration status and arrive where needed Manually Arrive your Goods in the UK.
If moving consignments containing controlled goods with pre-lodged declarations, read the List of Goods Imported into Great Britain from the EU that are Controlled and attend port inspection facilities or inland border facilities for goods to be inspected and released.
Exports should have Permission to Progress (P2P) before travelling.
We apologise for any inconvenience this may cause."
Additionally, HMRC have provided guidance documents for the release of CDS 5.1.0. These can be viewed below:
Posted on Monday 16th March 2026