The problem with most sales invoices and credit applications, says Robert A. Weissman, an Encino, Calif., lawyer, is that they don't always ensure collectibility. His checklist of key phrases to add:

* On invoices:

Late service charges. Always include one on the invoice, to collect as much as possible to cover your own expenses. Courts will recognize the additional liability.

Venue provision. If you ship products out of state, this provision requires purchasers to agree to allow any court case concerning your goods to be heard at a court in your own, presumably friendlier, locale.

Customer obligation. The customer must immediately examine goods and notify your office of problems within a specified number of days. "That eliminates a popular courtroom defense," Weissman says.

* On credit applications:

Attorney's fees. Most states set limits on how much can be collected (without a written agreement), but you can ensure you'll recoup at least some of your legal costs for pursuing overdue accounts. Just make sure your customer's credit application was signed by someone high enough in management to bind the company -- the CEO, for example.

A nontransfer clause. A statement saying that the "customer cannot transfer or assign the account relationship without your written consent" protects your ability to be paid even if your customer's ownership or corporate structure changes. As long as you withhold consent, you can still collect funds from whoever backed up the original credit agreement.

Credit-information release. Ask customers to sign a release that "authorizes creditors to release relevant information," Weissman says, to increase your chances of spotting problem debtors in advance. -- Jill Andresky Fraser