Why does an invoice ask for my license or a permit number?

Some trades have numbers that belong on the customer's copy — a plumbing or electrical license, an EPA 608 certificate, the permit pulled for a water heater, a repipe or a panel change. DeskOps asks for them only when your trade and the work on the document call for them, and it prints them on the invoice and the customer's pay page. Your business credentials are asked for once: type a number on any document and it is saved and filled in from then on, or set it in Settings under Trade credentials. A permit number is asked for on the invoice, never on a quote, because it does not exist until the customer has approved the work — and it is asked for on each job, because a permit belongs to one job: the last one you typed is offered beside the field ("Last used … use it only if this job is on the same permit") so a follow-up visit is one tap, and a new job never goes out under an old permit. A quote for a plumbing job asks only for the license.