How Does it Work?
If you encounter an issue when billing directly to Telus from the appointment checkout, the status on the appointment will display 'billing error'. At this point you will need to void the invoice in order to clear the status and try billing again.
You can add a customized Void Code such as 'Telus Billing Error' to use for these purposes. To do this, enter Settings > Void Codes, and add a new code.