What happens if the client loses the images? Include if you will be liable or not. (I’m not.) It’s the client’s responsiblity to backup photos in a safe place. You are not required to replace their photos free of charge if their obnoxious triplets, Bodean, Buck & Bucephelus used your disk of images as clay pidgeons during target practice. If there was a fire and someone lost everything AND I still had their archive from several years ago, I would consider replacing the digital images.