Invoice vs. Estimate: What's the Difference?

The short version

Think of an estimate as "here's roughly what this will cost" and an invoice as "here's what you owe." Estimates help a client decide whether to hire you. Invoices get you paid once you've done the work.

What an estimate is for

An estimate is your best educated guess at the cost of a job when you can't know every detail yet. A plumber can't always see what's behind a wall. A landscaper may not know how much soil needs replacing until digging starts. The estimate sets expectations while leaving room for changes.

Good estimates are still specific. Break the job into labor and materials, note what's included and what isn't, and explain what could change the price.

ESTIMATE EST-0031 — Water heater replacement
Labor (est. 4–5 hrs × $95) = $380–$475
50-gal gas water heater + fittings = $1,150
Estimated total: $1,530–$1,625
Note: Final price may change if the gas line or venting needs updating. We'll check with you before doing any extra work.

If you'd rather commit to one price, that's a quote. Quotes are fixed offers usually valid for a set period; see invoice vs. quote for how they compare.

What an invoice is for

An invoice bills the client for the actual work. It lists what you did, the final amount, the due date and how to pay. If the job cost more or less than the estimate, the invoice reflects the real number, ideally with a note explaining any difference the client already approved.

Going from estimate to invoice

1. Send the estimate and get the client's approval in writing (an email reply is better than nothing).
2. Track changes as the job goes. If something adds cost, tell the client before you do it.
3. When the work is done, create the invoice using the estimate's line items as a starting point.
4. Update quantities and prices to match what actually happened, and reference the estimate number.
5. Subtract any deposit already paid and send the invoice with clear payment terms.

Can an estimate be legally binding?

It depends on the wording, what the client signed, and your state's rules. Some states have specific rules for estimates in certain trades, like auto repair or home improvement. If you're unsure, check your state's requirements or ask an attorney. Clear language like "estimate, subject to change" helps set expectations either way.

Tools for estimates and invoices

Use the free estimate maker to put together an estimate and the invoice generator to bill when the job is done. The contractor invoice template is built for jobs with labor and materials. Trades that estimate a lot, like plumbers and contractors, have their own invoice pages with suggested fields.

In the BePaid iPhone app, estimates are handled as quotes: you create a quote and convert it into an invoice when the work is done, so you don't retype the line items.