Businesses Advised to Complete Customs Declarations Early Before Planned HMRC System Maintenance
HMRC Customs Declaration Service Downtime; Businesses importing and exporting products to and from the UK are being advised to get their customs paperwork in early this weekend after HM Revenue & Customs (HMRC) said the Customs Declaration Service (CDS) will be down for six-and-a-half hours.
CDS will be taken offline for routine maintenance by international-trade advisers Strong & Herd LLP from 20:00 on Saturday 4 July until 02:30 on Sunday 5 July 2026.
The New Computerised Transit System (NCTS) will still be available during the outage theoretically, however HMRC has advised that some transit statements sent between 20:20 and 23:10 would be queued until the service is restored.
What Is the Customs Declaration Service (CDS)?
The CDS (Customs Declaration Service) is the UK’s single system for making import and export entries and offering pre-arrival information to Border Force and port community systems.
While from an IT-maintenance viewpoint such a long period of unavailability can be commonplace, from a real-world perspective it might cause issues for logistics managers running just-in-time supply chains or handling time-sensitive consignments such as clinical trials, aeroplane supplies or fashion samples.
Potential Impact on UK Importers and Exporters
Movements that use a pre-lodged declaration while the declaration itself is in a queue will not be “arrived” at the border.
Transit movements may also be delayed for permitted consignee or consignor facilities while queued communications clear.
These temporary disruptions may affect businesses that rely on fast-moving supply chains and time-critical deliveries.
HMRC Advice for Traders and Customs Brokers
HMRC’s advise is that traders and customs brokers should make entry as far in advance of 20:00 as practicable and ensure that trucks, air-freight consoles and containers containing regulated products present themselves at inland border facilities or port inspection locations well ahead of the cut-off.
Businesses should have fall-back paperwork (e.g. transport Accompanying paperwork produced earlier in the day) and inform drivers on the prospect of being held pending validation where consignments have to move during the downtime.
Why This Planned Downtime Matters
The experience is another reminder of the fragility of border-IT ecosystems that international mobility and supply-chain teams rely on, even when the planned repair is brief.
Companies that are moving staff, transferring domestic goods or hand-carrying corporate equipment should confirm with their customs agents that entry have cleared before transportation begins.
Employers using “global business mobility” routes should also be aware that delays in goods could impact on the timing of assignee arrivals and any just-in-time work start deadlines associated with project equipment.
Impact on Travellers
There is no change at the passenger channel that travellers will perceive, it is the goods flows that are affected in practice.
However, mobility managers who have staff hand-carrying commercial samples or relying on unaccompanied personal items should allow for the possibility of a half-day delay to release timings and advise relocating staff accordingly.
Key Takeaways
Businesses involved in UK imports and exports should plan ahead for the scheduled Customs Declaration Service (CDS) maintenance window between 4–5 July 2026.
Submitting customs declarations early, preparing supporting documentation, and coordinating with customs brokers can help minimise disruption during the planned downtime.
Companies handling time-sensitive shipments, regulated goods, or international staff movements should pay particular attention to HMRC’s guidance to avoid unnecessary delays.