Invoice, estimate or quote: what is the difference?
An estimate says what the work will probably cost, a quote fixes the price, and an invoice asks for payment. When to send each one.
Estimates, quotes and invoices look alike, which is why they get mixed up. They do different jobs at different points in a piece of work: the first two are sent before it, the last one after.
Estimate: what it will probably cost
An estimate is your best judgement of the price before the work is fully defined. It tells the customer roughly what to expect and usually says how long the figure holds. Because the scope can still change, the final bill can differ from it. Use an estimate when the amount of work is uncertain, and say so on the document.
Quote: what it will cost
A quote, or quotation, is a firmer offer: a fixed price for a defined piece of work, valid until a stated date. Once a customer accepts a quote, they expect to pay that price. Use a quote when you know exactly what you are delivering.
In everyday use the two words overlap, and many businesses say "estimate" for both. What matters is that the document itself is clear about whether the price is fixed or approximate.
Invoice: please pay
An invoice is a request for payment for work done or goods supplied, or for a deposit or instalment you have agreed in advance. It has its own number, an invoice date, a due date and payment instructions. It is the document your customer's accounts team processes, and the one you keep as a record of what you are owed.
Side by side
- When it is sent. Estimate and quote: before the work. Invoice: when payment is due.
- What it asks for. Estimate and quote: a decision. Invoice: money.
- Key date. Estimate and quote: valid until. Invoice: payment due.
- Payment details. Not needed on an estimate; essential on an invoice.
- Numbering. Keep estimates in their own sequence, so they do not leave gaps in your invoice numbers.
How they fit together
- You send an estimate or quote.
- The customer accepts it, ideally in writing, and gives you a purchase order number if they use them.
- You do the work.
- You send an invoice that matches what was accepted: the same items, the same prices, and the purchase order number.
The last step is where mistakes creep in, because the invoice is often retyped from the estimate. If your invoicing tool can convert an accepted estimate into an invoice, use that instead; the two then cannot disagree. This is how the Tidy Invoicer estimate maker works.
Which one should you send?
- The customer asks "roughly how much?": an estimate.
- The customer asks "what is your price?" for something well defined: a quote.
- The work is done, or a deposit is due: an invoice. See what to put on it.
This guide is general information, not legal or tax advice. Invoicing rules differ between countries, so check what applies where you do business. Updated .