The functions performed in that office will be carried out at the firm’s sites in Kingswood, Surrey.
The company also has an office in Cannon Street, London.
The company said “the majority” of the staff employed in Tonbridge will have the opportunity to relocate, but there may be some job losses.
A process of consultation with staff will start in 2018.
Peter Horrell, UK managing director at Fidelity International, said: “We have to work in different ways to deliver for our clients and that includes being more efficient, more collaborative and working with more flexibility.
"We believe it is much easier to achieve this with one suburban site rather than have our infrastructure and our staff spread across two.
“Closing an office is never an easy decision to make but it is our clear intention and also our strong desire that the majority of people who work in our Kent office will come with us to Kingswood in Surrey and continue with their roles in a different location.”
He said the decision to retain the Surrey office is because the company believes it offers “the best chance” for the company to create a working environment suitable for the 21st century.
The axe fell on Fidelity's Tonbridge office just a week after it was announced Richard Parkin, head of pensions policy at Fidelity International, was to leave the asset management giant after 15 years.
A Fidelity spokesperson confirmed Mr Parkin was leaving Fidelity "of his own accord".
With the birth of his new son, the spokesperson said Mr Parkin had decided he would like to have a few months off with his family and to take some time to think about the next stage of his career.
However, the spokesman for Fidelity confirmed Mr Parkin will continue to focus on retirement policy and proposition.
Last month questions were asked by investment advisers about how Fidelity's new fee structure will work in practice.
At the start of October Fidelity announced its intention to move all of its funds to a new share class with “variable” fee structure, with a refundable performance fee.
The company said investors who move to this new share class will pay “significantly” lower fees, but because Fidelity will not be absorbing fund research costs, those who remain on the existing share classes will pay more.
The performance fee will only be levied if the funds achieve performance that is superior to that of the benchmark. If performance subsequently dips below the benchmark, the performance fee will be returned to investors.
The company justified its decision not to follow in the footsteps of rivals such as JP Morgan Asset Management and Artemis and absorb research costs by stating that as it has clients both within and outside the regions covered by Mifid regulations, and so if it were to absorb the costs, it would be effectively charging different prices to clients of the same funds.
david.thorpe@ft.com
