One of our clients was an Orthodontic Practice. Parents weren't paying for their Initial Consultation on the day of the consultation. "Please send me an invoice", being the most common answer to the Receptionist when asked "Would you like to pay for your consultation today?". The invoice was sent out (extra work), and parents were followed up if the invoice wasn't paid, which happened quite frequently (extra work).
So, we asked a couple of questions and this is what we did to solve the problem.
1: We gave the Receptionist a short script to follow for when an appointment was being made. Part of that phrasing was "We take payments for initial consultations when you come in. Will you be paying by cash, credit card or eftpos?"
2: a short letter or email was sent to the client to confirm the appointment and to mention that payment could be made by cash, credit card or eftpos.
3: After the consultation, the Receptionist added the word HOW to her question about payment ... "HOW would you like to pay for your consultation today, by cash, credit card or eftpos?".
Did this work? A resounding YES. Why? Because the client was told three times (on the phone, by letter/email and, finally, in person in the Waiting Room - with other people looking on.)
MOTTO: Don't ask a Yes/No question if possible. Plant the seed about payments a few times and then ask HOW.