Invoice or estimate, what is the actual difference?

"Can you send me a quote" and "can you invoice me" might sound like the same request in everyday conversation, but an estimate and an invoice are two completely different documents with different purposes. Mixing them up can create misunderstandings with a customer, and in the worst case, payment disputes.

What is an estimate?

An estimate is a proposal, a bid on what a job or a product will cost, before any work has been carried out. It is not, in itself, binding for the customer to pay, it is an invitation for the customer to accept or decline. A good estimate describes what is included, what is not included, the price, any reservations, and how long the price is valid.

What is an invoice?

An invoice is a demand for payment for a good or service that has already been delivered, or that will be delivered under an agreement. Unlike an estimate, an invoice is a bookkeeping document, it must follow bookkeeping law regarding sequential numbering, VAT rates, and mandatory details, and it creates a payment obligation for the customer.

How the process typically works

A common flow looks like this: you send an estimate to a prospective customer, the customer accepts it, you carry out the work or deliver the goods, and you then send an invoice based on what was quoted. If the customer wants changes along the way, you adjust the estimate or agree on additions before invoicing, rather than simply sending an invoice that deviates from what you originally agreed.

Common mistakes

One common mistake is sending an invoice before the customer has actually accepted anything, which can easily come across as pushy and damage the relationship. Another is never writing down what the estimate actually included, which makes it hard to prove what was agreed if a dispute arises later.

In FakturaKlar you can create an estimate, let the customer respond directly via a link (accept, decline, or request changes), and once it's approved, the step to creating an invoice for the same customer and the same line items is short, without rewriting everything from scratch.