HMRC intends to give importers up to six months to submit customs declarations and pay import duties in the event of a no-deal Brexit on 31 October.
HMRC says the new rules have been designed to 'ease congestion if the UK leaves the EU without a deal'.
Previously, businesses have had to apply for the Transitional Simplified Procedures (TSP) scheme. HMRC has now automatically registered 95,000 more VAT-registered businesses that import from the EU. The tax authority says this will make importing after Brexit simpler.
TSP arrangements will become active if the UK leaves the EU without a deal, from the date of its departure. Businesses using the TSP scheme will still have to check if their goods attract tariffs and obtain a Duty Deferment Account if they do.
Commenting on the scheme, HMRC's interim CEO, Jim Harra, said: 'We are doing everything we can to help businesses get ready for Brexit on 31 October. This move will support the trade of thousands of businesses, and is part of our longstanding policy of making sure we continue to keep trade flowing.'
Dr Adam Marshall, Director General of the British Chambers of Commerce (BCC), added: 'At a time of change, the top priorities at the border have to be keeping trade flowing and minimising the potential for disruption. Automatically registering companies for TSP at the border means one less immediate demand on traders' limited time and resources in the unwanted event of a no-deal exit.'