Customers will pay 50% of the annual management charge (AMC) on funds, until 5 April 2014, when they invest directly in a Fidelity ISA between 6th September and 30th November 2013.

The group said the promotion marks a series of improvements to its guidance service which launched in February in a bid to fill the “guidance gap” left by the Retail Distribution Review (RDR).

Under the RDR rules, which came into force on 1 January, advisers have to charge clients for their services and can no longer rely on commission.

According to a report by Fidelity and the Cass Business School earlier this year, as many as 43 million Brits could fall into what they call a “guidance gap” as a result of the RDR.