Estimate vs Quote vs Invoice: What's the Difference?

No. An estimate is your best guess at the cost before you know every detail, often given as a range ("$550 to $750"). It helps the client decide whether to go ahead, and the final price can move once you see the job.

A quote is a fixed price for a specific, written scope of work. It usually has a "valid until" date, because your material costs and your calendar change. If the client accepts it before that date, that is the price for that work. Anything outside the scope becomes a new quote or a written change, not a surprise on the bill.

Some trades and countries use the words differently, and how firmly an estimate or quote binds you depends on local rules. Whatever you call the document, say on it in plain words whether the price is fixed or approximate.

No. A quote comes before the work and asks "do you want this, at this price?". An invoice comes after the work, or a stage of it, and says "this is what you owe, please pay by this date".

The two often carry the same line items and the same total, because the invoice bills exactly what the client accepted. What changes is the question the document asks: a quote asks for a yes, an invoice asks for payment. That is why a quote has an Accept button and a "valid until" date, and an invoice has a Pay button and a due date.

Not as it stands. A quote does not ask for payment and has no due date, and your client's bookkeeping, and often your own records and tax filings, expect an invoice with its own invoice number and issue date. Send an invoice even when every line matches the accepted quote.

You do not have to retype it, though. Carry the line items and total over from the accepted quote, by copying them or by converting the quote in your invoicing tool, so the client sees exactly the numbers they agreed to, and add the quote number for reference.

Ask two questions in order. Is the work finished, or is a deposit due now? Then it is an invoice. If not, can you see the whole job well enough to fix a price? Then send a quote. If you cannot, send an estimate and follow it with a quote once you have seen the job or agreed the scope.

For contractors and other trades, a site visit is often the step between the two: a phone estimate gets you through the door, the visit gives you what you need for a fixed quote.

Whichever you send, the step after a yes is the same: an invoice for the agreed amount, or for a deposit first.

• Estimate: an approximate price, often a range, that can change.
• Quote: a fixed price for a defined scope, valid until a stated date.
• Bid: a price submitted to win a job against other businesses, usually in answer to a request for bids, common in construction and public contracts. In practice it works like a quote.
• Proposal: a longer document that explains how you would approach the work, with options, a timeline and the price. Agencies and consultants use it when the client is choosing an approach as well as a price.

A proforma invoice looks like an invoice but is sent before the work is done or the goods are shipped, to show the client exactly what the final invoice will say. Importers use it for customs and bank paperwork, and some businesses send one to request payment upfront.

A quote invites the client to accept a price; a proforma invoice confirms the details of a sale that is about to happen. Neither replaces the final invoice. Whether a proforma counts for tax or accounting purposes varies by country, so check with your accountant if you use them.

1. Quote: you send it; the client accepts the price.
2. Purchase order (PO): some business clients send you one after accepting, as their internal approval to spend. Put its number on your invoice.
3. Invoice: you send it once the work or a stage is done, or a deposit is due; the client pays by the due date.
4. Receipt: you send it after payment, confirming the money arrived.

In i-quote you send a quote with your business's name, logo and colour and a "valid until" date. Your client opens it on any device and accepts or declines it online. Once it is accepted, one click turns it into an invoice with the same line items and total.

If the quote asks for a deposit, the invoice is issued as soon as the client accepts, and they pay at least the deposit by card from the invoice page. Card payments go through Stripe straight into your own Stripe account, at Stripe's standard fee only; i-quote adds no fee per invoice. Automatic reminders then follow up on anything still unpaid, and a receipt goes out when it is paid.

The invoice carries the same items and total as the accepted quote, plus a due date and a Pay button. Your client can pay by card from their phone in about a minute.