Reports said Wirecard hsa been providing services for Revolut, Timit, Stocard, Soldo, ANNA Money as well as Curve.
ANNA messaged customers to say their money was frozen but "remains safe", saying "it may take time for the FCA to release the money."
Curve issued a statement saying it was looking to bring card issuing and e-money in-house and move away from a reliance on Wirecard. It said the disruption would last "for a limited time only."