Curve Metal cardholders can top-up fee free (subject to fair use).
Curve Black cardholders can top up fee-free for up to a total of 1000 GBP per month across all Amex Wallets on their Curve account (not per wallet). There is a 0.65% top-up fee thereafter.
Curve Blue cardholders will be charged 0.65% top-up fee each time they top up their Amex wallet.
For more information, please see the Curve Terms of Service.