What goes on a work order
- A work order number and the date it was issued
- Who is authorizing the work, with a contact and a phone number
- The contractor or technician, and the crew if it matters
- The site address, unit number and access instructions
- The scope — one line per task, with quantities
- Who supplies materials, and who disposes of waste
- The scheduled date and the expected duration
- The price, the hourly rate, or a not-to-exceed amount
- A signature line for authorization and a completion note
Work order vs purchase order vs invoice
A purchase order is a buying document. It commits money to a supplier for goods or services and follows a purchasing process. A work order describes a job at a site: what needs doing, where, when and for how much. A invoice asks to be paid once the job is done.
In practice, a maintenance team may raise a purchase order for the spend and a work order for the actual visit. If you are the contractor, the work order is your authorization; if you are the buyer, it is your record of what you agreed to. The purchase order generator covers the buying side.
Change orders: the text message is not enough
Most disputes about service work are not about the original scope — they are about the extra hours nobody wrote down. When the job grows, issue a change order or a new work order with the added tasks and the new price, and get it approved before the crew starts. That protects the contractor from unpaid extras and protects the client from a surprise invoice.
Site access and safety
Put the practical details on the work order: gate codes, parking, the site contact, working hours, lock-up rules, and any permit or safety requirement. A technician who arrives without access burns billable time, and that argument is always easier to win when the instructions are printed on the sheet.
Close the loop
When the work is finished, note what was actually done and have the site contact sign off. The contractor then raises an invoice that quotes the work order number, and the two documents match line for line. If the scope changed, the approved change order sits between them.