It’s just a piece of paper, often only one sheet and different companies write it up different ways. Yet when needed, the change order could prove the only thing that stands between you and hundreds or thousands of dollars’ worth of misunderstanding-or worse, unauthorized work that inflates the price of a project.

This addendum to the original contract ensures the service provider and customer are on the same page and that both sign the dotted line before making any changes to a job already in progress.

“You need to have a written record of the project”, says Robert Criner, founder of the Criner Remodeling, in Newport News, VA. “It keeps the job running smooth and there aren’t any surprises for anybody”. Criner serves as Vice Chair of the NAHB Remodelers, which represents the National Association of Home builder’s remodeling industry members.

For a construction or remodeling job-a common place for a change order- it details that project-already-underway switch tiles styles in the bathroom or outlines additional work a contractor needs to do after finding rot under the floor. The written agreement should communicate changes to job scope, how these impact cost, when you’re expected to pay (if it adds to the price tag) and any changes to the project completion date, since changes often push that deadline back, Criner says.

He prefers to call them “change requests” since they’re optional. That’s another reason to get changes in writing first, experts say, so you can review the details before proceeding with work.

Highly rated contractors say most change orders occur as a result of customers’ suggested tweaks once the project has started. Unforeseen issues can legitimately result in change orders on the contractor’s side too, but experts caution consumers to be wary of an endless stream of paperwork. “Unfortunately, there are contractors out there that rely on change orders to make their margins”, says Charlie Griffey, owner of Griffey Remodeling in Columbus, Ohio. “When you hear about people low-balling their estimates, it comes down to how detailed is their proposal and scale of work”?

In advance of signing off on any project, you should expect a thorough proposal that not only outlines what you’ll physically see in the space-the new divider wall and paint color-but also what you don’t, such as that pre-formed base put in before a shower install to prevent leaks.

“It is not unusual to have a six page proposal on even a bathroom remodel”, says Griffey, adding that this helps keep change orders to a minimum. “If it’s not a detailed proposal or scope of work, there’s always going to be change orders”. On the other hand, highly rated contractors say the lack of any change orders to account for modifications make to a project already in progress is also a red flag.

Consumers and contractors should work closely to determine early on if changes in project scope might be needed. Good communication nurtures the relationship, in person and in writing.