Quote vs Estimate vs Invoice: When Should You Use Each?

Quotes, estimates, and invoices are not interchangeable steps in a project. A quote or estimate helps a client understand expected work and cost before the engagement is underway. An invoice requests payment for work, items, or a milestone that is now due.

Quote — before the client decides; describes proposed work and pricing
Estimate — before the final scope is certain; shows expected range or cost
Invoice — when payment is due; requests an amount for completed work or a milestone