"familiar customer" is correct and can be used in written English.
You can use it when referring to someone who is a regular customer at an establishment. For example, "We have many familiar customers who frequent our restaurant."
Ms. Leary is becoming a familiar customer to the drivers of the cab company she calls the night before to set up her predawn rides.
BRADLEY BEACH, N.J. — Irene Maravelias was standing behind the counter of her popular deli here when she spotted a familiar customer, eating a Greek salad wrap and wearing shorts, a floral T-shirt and flip-flops.
They would allow shoppers to still comb through the merchandise — with the help of Nordstrom's familiar customer service — but the clothes would be delivered rather than carried out.
In addition, a community bank might be in a better position to evaluate a borrower's creditworthiness when there are extenuating circumstances with a familiar customer.
Familiar Customers, Unexpected Chic J. C.'s Hair Extraordinaire East is a place of little stories.
But in general even affluent consumers prefer traditional stores, because they are closer to home, are usually open longer and offer credit to familiar customers.
Clots of hard hats from the pit grin at the bar, familiar customers now after weeks of free, quasi-secretive feedings away from the emergency-zone commissary.
She collected the dyed baskets, olive wood and camel bone kitchen utensils, colorful multipurpose wraps and beaded sandals she said were "made by two guys who sit under a mango tree" and had private sales for familiar customers.
There's a heavy dose of critical slash and burn (Amis Jr and Woody Allen are among those left blistered and bleeding), with much praise accorded to such members of the "slash-and-burn school" as the Bard-baiting scholar and scalpel-for-hire Marvin Mudrick and the beatnik-New Journalist hybrid and "failure" Seymour Krim, as well as to more familiar customers such as Norman Mailer.
But as too many of these institutions have fallen into the habit of appealing to familiar customers, they must learn new methods of audience development.
When he does, he sometimes sees one or two familiar faces, customers who have just left the gym.
