Quote vs invoice: what's the difference (and when to send each)

March 4, 2026 · 4 min read

If you run a service business, you'll send both quotes and invoices constantly. They're easy to confuse, but using the wrong one at the wrong time costs you money.

A quote is a promise of price

A quote (or estimate) goes out before the work. It tells the client what you'll do and what it will cost. It isn't a request for payment — it's you saying "here's the deal." Good quotes carry a valid-until date because prices and availability change.

An invoice is a request for payment

An invoice goes out during or after the work. It's a legal request for money, usually with a due date and payment terms. Invoices are numbered sequentially for your records and the client's.

The handoff between them

The cleanest workflow is: client accepts a quote, you do the work, you convert that quote straight into an invoice — no retyping line items, no transcription errors. QuotationHero does this conversion in one tap, carrying every line item, tax, and discount across automatically.

• Send a quote to win the work.
• Convert it to an invoice to get paid.
• Track which quotes are pending and which invoices are overdue in one place.