Estimate vs quote vs bid: what a customer is agreeing to

When should I send an estimate instead of a quote?

Send an estimate when part of the price depends on something you have not measured or seen yet. Say what it is based on and what will firm it up. A roofer pricing from satellite imagery at $550 a square might say 20 to 24 squares, so $11,000–$13,200, final price after measuring.

A good estimate gives the customer a budget and a next step. Use a range or an hourly allowance, never a single number that looks fixed. Name the visit minimum if you have one, and say who buys materials. Tell the customer when you will stop and ask before going over, so the estimate never turns into a surprise invoice.

What makes a quote different?

A quote is an offer: this work, this price, these terms, accept by this date. After measuring 23 squares, the roofer quotes $12,650 for tear-off and architectural shingles, with replacement decking at $90 a sheet only if rotten boards turn up. Shepherd and Sons in Keller, Texas publish $450–$750 a square and $75–$110 a decking sheet.

Put the expiry date on it (materials prices move), how to accept (a signature, a reply, a deposit) and what is not included. Keep the accepted version. In California, the Contractors State License Board requires a written contract for any home improvement job over $500 in labor and materials, and changes to it must also be in writing. Other states have their own rules, so check yours before your first big job.

Is a bid always a fixed price?

Usually, but not always. A bid is whatever price format the buyer asked for, sent so they can compare you with other contractors: a total, unit rates, an hourly schedule or several options. Follow their format exactly, or your number gets set aside because it cannot be compared. Put your exclusions where they will be read.

Homeowners use the word loosely ("get three bids" means "get three quotes"). Property managers, HOAs and offices mean it more strictly: a deadline, a scope they wrote, sometimes a required insurance certificate. For a monthly office-cleaning bid, state the price per visit, the rooms and frequency covered, and the one-time price for the first deep clean as a separate line.

What happens when the job changes after the quote is accepted?

Write a change order before doing the extra work. On the roof above, the crew finds 6 rotten decking sheets after tear-off. At the quoted $90 a sheet, that adds $540, so the new total is $13,190. The homeowner signs or replies to approve, and the final invoice shows the quote, the change and the total.

Because the quote already named a per-sheet price for decking, this change is quick to approve. That is the reason to price likely surprises in the quote itself. The estimate, the quote and the change order each answer a different question on the same job: what will it roughly cost, what exactly will it cost, and what changed.

Frequently asked questions

Sources

• Shepherd and Sons: Keller, Texas roof replacement · Checked 2026-10-15

  Keller, Texas, architectural shingles with ridge vent and valley flashing included. Replacement decking is charged by sheet.

• Contractors State License Board (California): What should I look for in a contract? · Checked 2026-10-15

  Written contract required for home improvement over $500; changes must be in writing.