Estimate vs. Invoice: What's the Difference?

Estimates and invoices are often confused because they contain similar information. The difference is timing and intent: an estimate is a proposal before work begins, and an invoice is a request for payment after work is agreed or delivered.

What is an estimate?

An estimate (sometimes called a quote) is a non-binding document you send before starting a job. It tells the client what you expect the work to cost so they can approve it. Estimates typically include the scope of work, itemized costs, and an expiry date. No payment is due from an estimate.

What is an invoice?

An invoice is a formal request for payment. You send it once work is agreed or completed. It includes a due date, payment terms, and a total amount owed. Unlike an estimate, an invoice creates an expectation of payment and is used for your accounting records.

When to send each

• Send an estimate when a client asks 'how much will this cost?' before committing.
• Send an invoice once the estimate is approved, or once the work is delivered.
• For long projects, you might send an estimate first, then invoice in stages (deposit, milestone, final).

Turning an estimate into an invoice

Re-typing an approved estimate into a new invoice wastes time and invites errors. In Invoiceflint you can convert an approved estimate into an invoice with one tap — the line items, client, and totals carry over, so you only change what's different.