Having trouble with customers who take their early-payment discount even when they don't pay early? Carl Hansen, president and CEO of Viking Engineering Inc., a Tarpon Springs, Fla., manufacturer, has a solution.

Instead of detailing the discount on an invoice, making it tempting to take the discount regardless of when paid, Hansen prints his early-payment price offer only on an eye-catching green coupon included with each bill. The separate coupon prevents payables clerks from honestly confusing the discounted price with the regular, net-30 billing. It also, says Hansen, "psycholog-ically grabs the customer and bumps us up on the list of people to be paid.'

Apparently, it works: Viking's average bill is paid in a respectable 35 days -- down from 55.

* * *