Virtual Cards
Add to virtual balance
Add a delta amount to the virtual balance of a card.
POST
Adds a delta amount to the virtual balance of a card, and returns the resulting balance in USD. Unlike Override virtual balance, which sets an absolute value, this endpoint applies a relative change.
The operation is idempotent: retrying a request with the same
x-idempotency-key returns the original result instead of applying the amount a second time. Requires an API key with access level 2 or higher.
Path parameters
Card identifier.
Headers
Unique key that makes the operation safe to retry. Reusing the same key returns the original result without applying the amount again. Requests with a missing or blank key are rejected.
Body
Amount to add, in USD. Must be greater than 0, with up to 2 decimal places.

