Credit card giant Visa has announced that it has partnered with Repay International to launch a new credit card that calculates and offsets the carbon emissions of the products and services it is used to pay for - but does so by grouping them into only 24 categories.

The card, which is only available to business customers, allows cardholders to access a web site to check their purchases, their carbon emissions per transaction and the way that the related emission will be offset.

"This new partnership means that we can offer members a green payment capability across Europe that addresses the increasing demand for sustainable initiatives," said Luc Janssen, head of Visa Commercial.

The initative is supported by NGO Conservation International and the Dutch applied science institute TNO.

Products and services bought are fed into a carbon calculator to determine the amount of carbon emissions released. Repay International says on its website " calculator is fine-tuned and continually updated to ensure the calculation is as accurate, relevant and complete as possible".

However when Businessgreen.com contacted Repay international to ask them how they could possibly know the exact carbon footprint of any product or service that is bought anywhere in the world, it was revealed the carbon calculator is not as accurate as users might think.

"We group products and services into one of 24 categories based on the merchant code of the transaction. The carbon emissions of a unit in that category is then offset," said a spokesman.

The group says money is then invested in forestry, renewables, energy efficiency and carbon capture projects to offset the generated carbon emissions on behalf of the company of the cardholder.

The new card follows the launch of a similar Visa "green card" from Repay, aimed at the consumer market.

Patrick Bunnik, chief executive at Repay International, said that the partnership with Visa highlighted the extent to which high profile brands attitude towards green initiatives was changing "from a possible threat to a great business opportunity".