New business rate bills will be issued on April 1 following a revaluation of just under two million non-domestic properties.

The charges will now be based on the rental value of properties on April 1, 2015. These could be dramatically higher than the values listed during the previous valuation, which took place seven years ago.

Research published this week by the Federation of Small Businesses (FSB) found that 36% of small firms expect to see their business rates increase from the start of next month, with 21% of these firms facing a bill rise of more than 40%.

Solicitors and property experts Howes Percival said average bills should increase by 10.6% with London and the south-east expected to see the biggest hikes owing to the rise in property prices there in recent years.

Several London-based agents told TTG they had not yet received details of their new business rates, although one said they feared “they would be going up significantly”.

An Abta spokesperson said: “The upcoming change will leave many businesses faced with significant changes in their rates.

“Abta supports the calls of business organisations and others for more to be done to soften the blow of such large rate increases on many businesses as the current proposed transitional relief options do not go far enough.”

Ahead of next week’s budget, Abta has called on chancellor Philip Hammond to address these issues.

“Many businesses may be ill-prepared for a sudden and sharp increase in their tax bills,” the spokesperson added.

Andy Stark, managing director, The Global Travel Group, stressed that “listening and providing support and assistance to members with the running of their own businesses will always be the number one priority”.

One agency says it has benefited from the revaluation, however.

Nicholas Harding-McKay, director at Travel Designers, claimed the agency, in Balham, south London, which currently pays £1,000 per year in business rates, will no longer have to pay any business rates from April.

“It’s one of the things I looked at when we decided to move from Clapham, where we were paying several thousand pounds in business rates per year,” he said.

The Valuation Office Agency website has a tool that enables business owners to estimate their rates bill for 2017-18.