Although the number of drivers taking the so-called "free" fuel benefit has dropped in recent years, statistics from HMRC reveal that in 2007-08 – the most recent year for which official figures are available – a total of 340,000 company car drivers continued to pay BiK tax on fuel used privately and paid for by their employer.

This is despite the fact that over the last decade the tax burden on such employees has increased year-on-year as part of a Government move to end the "perk". These tax rises mean that only a handful of drivers will benefit from continuing to receive free fuel – these are typically drivers of very low-emission cars and those who clock up extremely high private mileages.

Jaama's new technology is intended to help drivers calculate whether they would be financially better off opting out of taking free fuel.

Managing director Jason Francis said: 'Given the advice over many years from financial experts it remains a mystery why so many drivers continue to receive "free" fuel.

'Our EDS module enables drivers to calculate exactly how much tax they are paying and how much fuel they are using privately. The system then gives employees the option of opting out of the scheme and reimbursing their employer for fuel used privately.

'It is likely in most cases that drivers will be able to save cash and their employers will save money in relation to the cost of fuel, National Insurance paid on benefits-in-kind and the VAT scale charge if the benefit was withdrawn.'