Estimate vs invoice — what's the difference?
An estimate and an invoice are both billing documents — but they serve different stages of a project and carry different levels of commitment.
What is an estimate?
An estimate is a document you send before work begins. It describes the scope of work, the expected cost, the timeline, and payment terms. It is a proposal — the client can approve, decline, or negotiate. An estimate does not obligate the client to pay. It creates written alignment before you invest any time in the project.
What is an invoice?
An invoice is a payment request you send after work is delivered or at a billing milestone. It states what was done, the amount owed, and the payment due date. An invoice is a legally binding request for payment.
When to send an estimate
- Before any work begins — especially for new clients, larger projects, or anything where scope could be disputed
- Any time you want written sign-off on price and deliverables before starting
- For recurring clients where the scope of a new project differs from previous work
- A signed or approved estimate protects both sides if there is a later dispute
When to send an invoice
- Immediately after delivering a milestone or completing the work
- The faster you invoice, the faster you get paid — do not wait
- For large projects, use milestone invoices tied to deliverables rather than waiting until the end
- For recurring retainer clients, invoice on the same schedule each month
Converting an estimate to an invoice
In Duevero, clients approve estimates via a shareable link — no account needed on their end. You convert the approved estimate to an invoice in one click, the description, totals, and client details carry over automatically, and the invoice references the approved estimate. No re-entering data.
Deposit invoices
Many service businesses send a deposit invoice (25–50% upfront) at the same time as the estimate, or immediately after the client approves — before starting work. The remaining balance is invoiced on delivery. In Duevero, send a deposit invoice from an approved estimate in one click.
Use Duevero for free — estimates and invoices in one place
- Create and send professional estimates with shareable approval links
- Convert approved estimates to invoices in one click — no re-entering data
- Send deposit invoices immediately on estimate approval
- Track payment status on all invoices
- Free Basic plan — no credit card required