These three documents are easy to confuse because they all deal with money and clients. But each one serves a different function, appears at a different point in the process, and carries different legal weight.
Quote
A quote is a conditional offer — it states what you will deliver and at what price before any work starts. The client can accept, reject, or negotiate.
A quote is not binding until the client accepts it. Once accepted, it becomes the basis of the contract between you. Keep signed or email-confirmed quotes on file: if a payment dispute arises, the accepted quote is your evidence of what was agreed and at what price.
Quotes typically expire after 30 days unless you specify otherwise. Including an expiry date on large projects protects you from a client returning months later expecting the same price.
Invoice
An invoice is a payment request for work already delivered (or about to be delivered under agreed terms). It is the formal demand for money and — in most jurisdictions — a legal document you’re required to issue for taxable transactions.
Issuing an invoice creates the payment obligation. Once sent, the client legally owes you the amount stated. It must include specific mandatory information: your legal details, a unique invoice number, a description of what was delivered, VAT treatment, and your bank details. Missing fields can make it legally invalid for tax purposes.
An invoice is not proof that payment was received. It says “you owe me this” — not “I received this.”
Receipt
A receipt is confirmation that payment has been received. It is issued after the money arrives — not when you send the invoice.
In many business contexts, a correctly formatted invoice with a “paid” notation (date and payment method) serves as a receipt. A standalone receipt is sometimes requested by clients who need to reconcile payments in their financial system against individual transactions.
For cash payments, a receipt (Quittung in German, under §368 BGB) is legally required even when a separate invoice exists.
When each document appears
| Stage | Document |
|---|---|
| Before work starts | Quote |
| Work delivered, payment expected | Invoice |
| Payment confirmed received | Receipt |
What about proforma invoices?
A proforma invoice is not a real invoice — it is a quote formatted to look like one. Banks, customs authorities, and some clients request them to confirm pricing before a formal commitment exists. They carry no VAT, create no payment obligation, and should never be booked as income.
In Billino
Billino lets you create quotes, invoices, and cancellation invoices (Storno) from the same interface. A quote converts to an invoice in one tap. Every invoice includes all legally required fields — including the §19 UStG Kleinunternehmer note if you’ve enabled it in your sender profile.
