Have you ever been in a customer-facing role?

"Maintenance work is often customer facing so yes, I have a great deal of experience in a customer-facing role. I am comfortable working with customers."

If you are able to be in a customer-facing role, this will be a big bonus to your current employer. Talk to the interviewer about any experience that you have working directly with customers.

"My earlier career was in a retail based customer service position and since then I have always had some sort of customer facing component to my position. I have a lighthearted personality and am able to easily connect with a variety of personalities. You can be comfortable knowing that your customers are in good hands with me."