"We have closed the exchange so that members can adjust their systems, where necessary, to take into account the exemption on VAT of carbon in France and also to let the members contact their customers and let them know," says Keiron Allen, communication and marketing director of Bluenext.

"We have been speaking with the French ministry over several months in efforts to get carbon exempt from VAT because of the large financial burden it puts on us as the central counterparty to manage that VAT,"