Government plans to roll out a new customs system by March 2023 is “not fit for purpose” and faces “huge challenges” technology specialists are warning.

The warning comes as the government announced this week that its Customs Declaration Service (CDS) will become the UK’s single customs platform from 31 March 2023.

The move will see HMRC close its legacy Customs Handling of Import and Export Freight (CHIEF) system on the same day with businesses required to declare all goods through the new Customs Declaration Service (CDS) from this date.

CDS is already used for Northern Ireland and Rest of World declarations and, although it has already processed more than one million declarations since it went live in 2018, its implementation for NI in January this year was fraught with problems and delays, which left trucks queueing at the borders.

Steve Bartlett, chairman of the Association of Freight Software Suppliers (AFSS), said “huge challenges” remain with the new customs system which must be tackled before any widespread migration from the legacy CHIEF system to CDS can happen.

He added: “In its current state CDS is not fit for purpose. It has not experienced significant load testing to give us the confidence that it will be able to scale up to the 380 million plus declarations it will need to process. In addition critical functional requirements to make CDS usable do not have a confirmed delivery date.

He said software suppliers are reporting that currently migrating traders to CDS is “like wading through treacle”.

He warned: “If large scale trader migrations are to happen the process has to be much smoother and far more rapid”, adding that with CDS entries taking almost four times longer than CHIEF entry the government may have to offer incentives to traders to make the switch.

HMRC said this week services on CHIEF will be withdrawn in two stages with import declarations closing on CHIEF on 30 September 2022 and export declarations closing on CHIEF on 31 March 2023.

In a joint statement, Sophie Dean and Katherine Green, HMRC directors general for borders and trade, said: “CDS is a key part of the government’s plans for a world-leading fully digitised border that will help UK businesses to trade and to prosper.

“This announcement will provide clarity for traders and the border industry. We are committed to making the switch-over as smooth as possible and are working to ensure traders are fully supported with the new processes.

HMRC added that CDS will provide a “more secure and stable platform with the capacity and capability to grow in line with the government’s ambitious trade plans. The move to one system for all imports and exports will also deliver savings for the taxpayer.”