In both new and used product sales, the manufacturer or seller may attempt to avoid the implied warranty of merchantability by either limiting it or disclaiming it entirely with an AS IS clause. All of the laws discussed above limit the effect of purported disclaimers. While disclaimers of implied warranties may be valid in certain situations, disclaimers of express warranties are never valid.

Under the UCC, for a disclaimer to be valid the seller must a) display the disclaimer language "AS IS" must be conspicuously displayed (no fine print), b) there cannot be a conflict between any disclaimer and what is represented verbally or in writing, and c) the seller must have "bargained" for the disclaimer, i.e. the buyer must know BEFORE they sign the contract that the implied warranty is being disclaimed.

Under Song Beverly, implied warranties may not be disclaimed if there is a written express warranty of any kind (including a service contract).