Invoice vs Estimate vs Quote: What's the Difference?
An estimate or a quote is a proposed price you send before doing the work, while an invoice is the bill you send afterward asking to be paid. In everyday use, "estimate" and "quote" mean close to the same thing — a starting figure that can still change — and the invoice is the only one of the three that is actually a request for payment.
What a quote or estimate is
A quote or an estimate lays out what a job is expected to cost before you start it. It gives a client something to approve, and it is not a bill — no payment is due just because an estimate exists. Some businesses use "quote" for a fixed price and "estimate" for a figure that may move once the real scope is clear, but neither term is standardized, so what matters more than the label is what the document itself says: the items, the price for each, and how long the price is valid for. A client can reject or ask you to revise a quote or estimate freely, since agreeing to it is exactly what turns it into a job in the first place.
What an invoice is
An invoice is sent once the work is done, or once it's agreed to be billed, and it asks for payment by a due date. It typically lists the same client and line items as the estimate that came before it, plus payment terms and, often, a way to pay directly from the document. Where an estimate is a proposal a client can accept or push back on, an invoice is a request that's already been agreed to — the negotiating, in theory, already happened at the estimate stage, so by the time an invoice goes out the open question left should be when it gets paid, not whether the price is right.
A note on legal or tax invoices
This isn't legal or tax advice, and requirements vary by country. In some places a "tax invoice" has specific legal requirements to be valid for tax purposes — Mexico's CFDI system is one example, where a sale generally needs a government-registered document to count for tax reporting. Invoice Maker creates commercial documents: invoices, estimates and quotes you send to a client, not government-registered tax invoices, so check your local rules if a formal tax invoice is what you need for a given sale. A commercial invoice can still be exactly what a freelancer or small business needs day to day — it's simply a different thing from a government tax filing, and the two aren't always required together.
Turning an estimate into an invoice with one tap
Once a quote or estimate is approved, redoing the same client and line items as an invoice would be a waste of time. In Smart Invoice & Estimate Maker (Invoice Maker) you can start with an estimate or a quote, then turn it into an invoice with one tap, carrying the details across instead of re-entering them. The same saved clients, items and tax rates you used on the estimate stay attached, so switching from proposal to bill doesn't mean starting the paperwork over.
The same tools, whichever document you're making
Invoice Maker draws on the same set of 100+ templates for its documents, so a quote and the invoice it eventually becomes can share a consistent look from proposal to payment. An invoice itself doesn't have to start blank, either — scan a paper invoice, or pick a photo of one, and it becomes an editable draft you can adjust. The app also carries features like discounts, shipping, payment methods, reusable terms and a handwritten signature drawn on your iPhone, the kind of detail that matters just as much on the bill as it did on the proposal that led to it.
One free allowance covers all three document types
Invoice Maker gives you three documents free, no account or sign-up needed. That's three in total, not three a month, and invoices, estimates and quotes all draw on the same allowance rather than three separate ones. A document only counts once, the moment you create it — editing it or sending it again later doesn't use up any more of the allowance, so a quote you revise twice before a client approves it still only costs one document from the free total. Beyond that, going Pro removes the limit and unlocks the rest of the app's templates and QR styles. See the Invoice Maker app page or the invoice template to get a document started.