Watch a report by ITV News Anglia's Claire McGlasson
Companies in the ITV Anglia region say new customs controls are causing delays and could lead to problems with supply.
The UK government brought in the new arrangements for goods imported from the EU on New Year's Day. Businesses say it is costing time and money to meet the regulations, putting extra strain on companies already struggling with the effects of Brexit.
Oranges grown in Spain for sale in UK supermarkets are imported by G's Fresh in Ely. The company is responsible for bringing in 400 lorry-loads of produce a week but the new post-Brexit rules are making the process more difficult.
The forms for each shipment taking as long as four hours to complete.
Kuldip Kular of G's said: "If it goes wrong, that could easily be delayed by one or two days which then has an impact on availability on the shelves here and also on the freshness of the product."
From the start of 2022 the rules involving customs and border checks on goods being imported from the European Union were tightened following a transition period during last year.
The changes mean goods being brought into the country from the UK will need all the paperwork to be complete and have customs clearing before they will be allowed to leave the port.
In 2021, companies were allowed to delay their customs declarations but now they will have to be completed immediately and any extra tariffs due must be paid at the time of importation.
The Suffolk brewer Adnams says it fears higher costs and more red tape.
Adnams' Chief Executive Officer, Andy Wood said: "Supply chains are starting to adjust but there is no doubt that there is much higher cost in the supply chain for businesses such as Adnams.
"We import wine from Europe and from around the world and there is no doubt there is higher cost in the system and there will be more bureaucracy and more paperwork."Turners, in Fordham near Newmarket, is now running six training schools for new lorry drivers.
Managing Director, Paul Day said: "When there's a shortage, then clearly drivers' wages have to go up. To retain the driver force that you have and to try to attract new entrants."
Whether it's paying higher wages or employing new staff to fill out extra paperwork, many businesses are still counting the cost of Britain's decision to leave the European Union.