The Deceptively Simple Purchase Order
An adjustment to the order is itself a contractual agreement, which also should be in writing. There are two ways to approach this. You can anticipate common adjustments and note in the P.O. how they will be handled. Or, if the adjustment is not anticipated, you can use a separate agreement signed by both the buyer and supplier.
AVOIDING A BIND
The most important fact to remember is that, unless you specifically state otherwise, a P.O. is legally binding. In most states, once the parties identify the paper quantity and one or both of the parties "reasonably" relies upon the expectation that that quantity will be supplied, the P.O. may be enforceable, even if it hasn't been signed by both parties or any other details are missing. If you do not want the other party to anticipate receipt or manufacture of the paper quantity specified, it is important to state in writing: "This purchase order is for discussion purposes only and is not binding."
If, on occasion, you accept and pay for paper supplied under an oral agreement, and subsequently switch to the use of written P.O.s, but do not require a signature, a court may infer that it was reasonable for the supplier
to rely upon an unsigned P.O. If you have already delivered an unsigned P.O. that does not contain a non-binding disclaimer, most state laws will permit you to retract the P.O. within 10 days of delivery.
If the supplier has already begun production, or the paper being produced is a special paper useable only by the buyer, then the sooner you retract the order in writing, the better.
The P.O. should contain all of the terms affecting the purchase. To avoid the unintended 'integration' of oral agreements or written messages into the P.O. provisions, the parties should specify that the P.O. contains the parties' "entire understanding" regarding the paper purchase in question.