Yes. And, you can control if this is possible.
First, its worth noting that payment will not be required when a staff member is booking the appointment for the customer.
But, when a customer is booking, you can choose if customers will need to pay to book the appointment. This can be controlled by clicking Appointments > Services > editing a service > scrolling to "Require customers to pay when booking on their own."
Momence tallies unpaid appointments on a customers account for you and unpaid appointments can quickly be found and paid for in POS. Just select the customer and choose Appointments. Or, have them log into their customer account. They will see unpaid appointments listed there and can pay there as well.
So how is payment taken handled later?
Customers with unpaid appointments that login to their account will see the following. The drop down menu to the right will allow them to pay.
If a customer is physically at your business and wants to pay in person, just pull up Point of Sale, select the customer, and choose Appointments to see a list of unpaid appointments.
To see a list of all Unpaid Appointments for all customers, click Appointments > Reservations > Filters > update Payment Status to only include Unpaid.
You can take payment from this page by clicking the dropdown menu to the right.