post https://sandbox.checkhq.com/payments//cancel
Cancel can only be used on ACH credit payments associated with funded payrolls that have a payment attempt which has not yet begun 'processing'. Payments with with these qualities have a 'pending' status. The can_cancel field is a boolean which describes whether or not a payment can be canceled.
Cancel must be used prior to the payment's fulfillment being sent out and the payment's status being set to 'processing'. This is denoted by the cancel_deadline field and is generally around 1 pm ET the day before the payday of the credit's associated payroll.
Canceled payments have a status of failed.
[08/15 Sandbox Only] Canceled payments have a status ofcanceled.