All payments for engagements are processed after the session has started.
On the day of a booking, payment will be automatically processed once the professional requests collection of funds at the start of a session, as long as there have been no cancellations by the professional or employer.
If there is any problem with the payment method, both you and the professional will be immediately notified that there has been a failure to collect the funds, and your Resonance account will be locked until you update your payment information.
It's up to the professional whether they want to continue services without payment, though we strongly encourage them not to do so.