The two firms have uncovered discrepancies in the emission figures quoted by motor manufacturers and the Society of Motor Manufacturers and Traders which could leave drivers hundreds of pounds out of pocket when the new tax system is introduced in 2002.
Nick Gafney, VELO's marketing manager, said: 'The SMMT website displays what is regarded as the definitive list recommended by the Inland Revenue, but we are trying to provide customers with reliable data on cars we are signing off now. How can fleets prepare effectively for tax changes when everyone is singing from a different hymn sheet?'
VELO's research has revealed discrepancies between the SMMT's figures and those compiled by independent fleet management software providers acting on the latest information supplied by manufacturers. The most glaring examples include a fleet favourite, the Peugeot 406 3.0 V6. The manufacturer's CO2 emission figure is 229g/km. The SMMT quote 265g/km. This discrepancy would amount to a difference of 8% in the taxable benefit and a difference in tax bill of up to £57 a month.
'Another complaint is that despite being named as the official source of CO2 figures, the SMMT site only provides information for vehicles registered between January 1998 and December 1999.
'It may be that manufacturers are issuing current figures that have yet to be updated on the SMMT's system, but there needs to be clarification. The Inland Revenue must take a clear lead and provide a definitive set of guidelines to all parties,' said Gafney.
Alastair Kendrick, director of PAYE/NIC solutions at Ernst and Young, said: 'The problem needs to be solved quickly to avoid complications when the new system comes into force.'
An SMMT spokesman said: 'It's retrospective data and we admit that if you want data on cars registered now you will be struggling. But we hope to have up-to-date data on the latest models soon.'