Revenue & Customs will need a new computer system to cope with increased customs declarations as a consequence of Brexit

Revenue & Customs has been warned that a new £70 million computer system to handle customs declarations will not be able to cope with the consequences of Brexit.

Theresa May’s announcement that Britain will leave the customs union could mean that all goods arriving and leaving the UK will require customs declarations. Business leaders say that would mean an increase from about 90 million to 390 million declarations a year by 2019 as EU goods movements are classed in the same way as imports and exports from third countries.

The present computer system, Customs Handling of Import and Export Freight (Chief), is 25 years old and was designed to handle 50 million filings a year. Its replacement, the Customs Declaration Service (CDS), had been intended