A work order is an authorization to do the work — scope, price, and often client approval. An invoice is a request for payment after (or as) the work is done. Many contractors use both: approve the work order, do the job, then send the invoice. TimeFotos lets you create an estimate, convert it to a work order, and then to an invoice — all in the same job workspace with your photos. Create your free listing → · timfotos.com/pricing. Start free →