Estimate vs invoice: the difference, and when to send each
Contractors use the words loosely and clients get confused, usually at the moment money is involved. The short version: an estimate is a promise about the price before the work. An invoice is a request for payment after it, or after part of it.
The estimate
Goes out before the job. It lists the work, the price of each part and the total, and it asks for a signature. Once signed, it is your agreement on scope and price. It does not ask for money by itself, though it usually says what deposit you need to start.
Quote and bid mean nearly the same thing in the trades. A quote is usually a firm price. A bid is a price submitted against others, on commercial or public work. An estimate can be either, and on residential work it is the word clients know.
The invoice
Goes out when money is due. It says what was done, what it costs, what has already been paid, and what is owed now, with a due date and a way to pay. You might send one invoice at the end of a small job, or several across a big one: the deposit, a progress payment, the balance.
An invoice can differ from the estimate, and often should. The change orders the client approved, the extra square footage, the item they added on Tuesday all belong on the invoice. What does not belong is a surprise: anything on the invoice that was not on the estimate should have been agreed before the work was done.
The easiest way to keep them in step is to build the invoice from the signed estimate rather than from scratch. Same lines, same numbers, plus what changed.
When to send each
- Look at the job. Send the estimate that day.
- The client signs. If you need a deposit, send the deposit invoice now, before you order material.
- Work. If the scope changes, write it down and get it approved before you do it.
- Finish. Walk the job with the client, then send the final invoice the same day, while the work is fresh and the client is happy.
What each one needs on it
- Both: your business details, the client's, the job address, a date, line items and a total.
- Estimate: how long the price is good for, what is excluded, the deposit and payment terms, a signature line.
- Invoice: an invoice number, what has been paid, the balance due, the due date, and how to pay. A card link gets you paid faster than "check or Zelle".
Common questions
Can I invoice more than the estimate?
Only for work the client agreed to after the estimate. Put each change on its own line so the client can see where the difference came from. Invoicing more than the signed estimate with no agreed change is how disputes start.
Do I need both for a small job?
For a one-day repair, many contractors send a single document that acts as both: the price up front, then marked paid when it is done. It works until the scope changes. Two documents cost nothing extra with an app and keep the record clean.
Is a signed estimate a contract?
In most states, once both sides act on it, yes. Bigger jobs usually deserve a separate written contract with the estimate attached as the scope and price.