A quote is an offer to do work for a stated price. An invoice is a request for payment after the work is done or goods are delivered. You send a quote before the job and an invoice after it.
| Quote | Invoice | |
|---|---|---|
| When | Before work starts | After work is delivered (or at agreed milestones) |
| Purpose | Tells the client what it will cost | Asks the client to pay |
| Key date | Valid until | Payment due |
| Accounting | No accounting entry | Creates a receivable and, if registered, a tax liability |
| Binding? | Becomes binding once accepted | Records a debt that is owed |
Quote, estimate or proposal?
In the UK and many other places a quote is generally treated as a fixed price for the work described, while an estimate is an educated guess that can change. A proposal is broader: it explains your approach and often contains a quote. If your price might move, call it an estimate and say what could change it.
Moving from one to the other
Once a client accepts, your invoice should mirror the quote line by line, plus any agreed changes. See how to convert a quote to an invoice.