Invoice vs estimate: what’s the difference?

The short answer

An estimate is sent before the work. It describes the job, lists the expected price, and asks the customer to agree. An invoice is sent after the work, or at an agreed stage, and asks for payment.

An estimate is not a bill. A customer who approves one is saying yes to the plan, and you still need an invoice to be paid.

How they differ

• Purpose: an estimate wins the job; an invoice collects the money.
• Timing: an estimate comes first; an invoice follows the work or a milestone.
• Price: an estimate can change if the job changes; an invoice is the final amount owed.
• Due date: an estimate has an expiry date for the offer; an invoice has a payment due date.
• Number: keep separate numbering, such as E-210 for estimates and 1042 for invoices, so they never get mixed up.

Estimate, quote or bid?

People use these loosely. In common use an estimate is your best guess and may move, a quote is a fixed price, and a bid is a price offered against other contractors. Say which you mean on the page. “This is a fixed price” and “This is an estimate; the final cost will be based on time and materials” are very different promises.

Some states have rules on written estimates for certain trades, such as auto repair and home improvement. Check what applies to you.

What an estimate should say

The more specific it is, the fewer arguments you will have at the end.

• The scope: what is included and what is not.
• A price, or a range, and whether it is fixed or based on time and materials.
• How long the price is good for.
• The deposit and payment terms.
• A way for the customer to say yes, such as a signature or an approve button.

When to use an estimate

• The job is big enough that the customer will want a price first.
• You want a deposit locked in before you buy materials.
• There is more than one way to do the work and the customer picks.
• You want the scope in writing, so “I thought that was included” doesn’t come up later.

When to go straight to an invoice

For small, quick jobs the price is usually agreed on the spot, so an invoice alone is enough. Repeat work at a known rate, like a weekly cleaning, is the same. If the customer has already said yes, skip the paperwork and bill.

From estimate to invoice

1. Send an estimate with a clear scope, price, expiry date and deposit, if any.
2. Get a yes in writing. A tap on an approve button or a reply email counts as a record.
3. Collect the deposit before you buy materials.
4. Do the work. If the scope changes, note it and agree the new price before you carry on.
5. Invoice for the final amount, take off the deposit, and send it the same day.

Copy the lines from the estimate to the invoice, then add extras. If the total differs, explain why in a short note. Our guide on how to write an invoice covers the rest, and the free invoice generator lets you try one.

Changes along the way

When the customer adds work, or you find something unexpected, write it down and get a quick yes before you carry on. A one-line text such as “Extra circuit, $340, OK to go ahead?” is a record. Put the change on the invoice as its own line so the total makes sense against the original estimate.

Where Paylark fits

Paylark is opening soon and turns an approved estimate into an invoice in one tap, with the deposit already taken off.