There will be times when your customers have a credit balance with your firm (credit on their account). Always tell the customer they have this credit. You may be wise to call their buyer to tell him of the open credit due to his company. This honesty may provoke him to buy something in order to use it up or he may tell you he wants it paid to his firm. Either way, do what he requests. Do not hesitate to mail him a check. If you refuse and tell him you will only take an order, it may be the last order you get from them. Think twice before refusing to pay it back.