If you're running a business, you've probably used the words "invoice" and "quotation" interchangeably. But they're actually very different documents — and using the right one at the right time can make or break a deal.
What Is a Quotation?
A quotation (also called a quote, estimate, or proposal) is a document you send before the work begins. It outlines what you'll do, how much it'll cost, and the terms — giving the client a chance to approve, negotiate, or decline before committing.
What Is an Invoice?
An invoice is a document you send after the work is done (or at agreed milestones). It's a formal request for payment — a legal record that says "you owe me this amount by this date."
Key Differences at a Glance
| Aspect | Quotation | Invoice |
|---|---|---|
| When sent | Before work begins | After work is done |
| Purpose | Propose scope & pricing | Request payment |
| Legally binding? | No (until accepted) | Yes |
| Payment expected? | No | Yes, by due date |
| Can be negotiated? | Yes | Usually not |
| Contains due date? | Validity/expiry date | Payment due date |
When to Use Each
Send a Quotation When...
- A potential client asks for pricing
- The project scope needs to be agreed upon
- You're bidding against competitors
- The client wants to compare options
- You need written approval before starting
Send an Invoice When...
- The work is completed
- You've hit a milestone (for phased projects)
- It's a recurring billing cycle
- The client has already approved the quote
- You need to collect a deposit before starting
Convert Quotes to Invoices with InvoW
With InvoW, you don't need to recreate everything from scratch. When your client approves a quotation, simply click "Convert to Invoice" — all the details (client info, line items, amounts) transfer instantly. No copy-pasting, no errors.
The InvoW workflow:
- 1.Create a quotation with all project details and pricing
- 2.Send it to your client for review
- 3.Client approves → click 'Convert to Invoice'
- 4.InvoW creates the invoice with all details pre-filled
- 5.Send the invoice and track payment status
This seamless flow saves you time and ensures nothing gets lost between the proposal and billing stage. Try it free on InvoW.