SNP ministers were blasted as it emerged the cost of their glitch-hit vaccine app could hit £1.2million.
Covid Recovery Secretary John Swinney revealed a contract with Netcompany has been extended.
It means the bill for the Danish firm would be double the original £600,000 despite major problems with the jab passport since launch.
Mr Swinney said the extra cost was connected to “new technical development work” and converting the tech for the Scottish Government domestic vaccine passports, which kicked in last month for nightclubs and large events.
But Tory shadow Covid secretary Murdo Fraser said: “The SNP are throwing good money after bad by persisting with their disastrous vaccine passports scheme.