Time etc client's have a "wallet" in their account that contains funds that they can spend on your Virtual Assistant services. When your client runs out of pre-purchased funds in their wallet you will receive an alert.
When a client runs out of funds, they have the choice to buy more. We recommend never doing work if a client has no funds because your fees may not be paid for the work that you do - and we are unable to guarantee them.
For greater detail on what to do when your client is out of funds go here.