Reference
Estimate terms: the words on an estimate and an invoice
Plain definitions of the terms on a repair estimate and invoice, from book time to core charge, then the example states' written estimate rules with the route to your own state's.
The words below are the ones on estimates, repair orders and invoices. Each says what the term means as the source uses it and what to ask. The estimate check rebuilds a total from its lines, and Reading a repair estimate walks through one.
| Term | What it means, and what to ask | Sources |
|---|---|---|
| Labor rate | The shop's price for one hour of labor. Labor on an estimate is the hours times this rate. Use the rate the shop posts or prints; published survey averages disagree with each other. California's rules do not require the rate on the estimate or invoice, so ask for it. | FTC, Auto Repair Basics; MOTOR, Mechanic Labor Guide usage tips; California BAR, Write It Right |
| Book time, flat-rate time | Labor hours taken from a labor guide's average time for that job on that car, charged whatever the job actually takes. MOTOR, a guide publisher, calls its times averages, not promises, and says severe rust and diagnostic hurdles are not in them. | FTC, Auto Repair Basics; MOTOR, Mechanic Labor Guide usage tips |
| Actual time | Labor charged for the hours the technician actually worked. The FTC names it as the alternative some shops use. | FTC, Auto Repair Basics |
| Diagnosis fee | A charge for the testing that finds the cause of a problem. Ask what it covers and whether it applies to the repair if you have the work done there. Michigan requires its cost on the estimate before diagnosis begins. | FTC, Auto Repair Basics; MCL 257.1332 |
| Tear-down estimate | An estimate for taking apart part of the car to find the problem, with the cost to put it back together if you do not go ahead. California lists what it must include. | California BAR, Write It Right |
| Shop supplies | Small materials such as rags and cleaners. California bars a generic supplies charge and allows only supplies actually used, itemized; Michigan requires an actual dollar amount, not a percentage. | California BAR, Write It Right; Michigan Department of State, Repair facilities |
| Environmental or hazardous waste fee | A charge for disposing of used fluids and parts. California requires it itemized with the shop's EPA ID number; Florida's estimate form discloses it with a set statement. | California BAR, Write It Right; Florida Statutes 559.905 |
| Core charge | A charge tied to the old part (the core) when a rebuilt or exchange part is installed. California BAR's guide says a core charge may apply if you keep the old part; ask whether returning it removes the charge. | California BAR, Consumer's Guide to Auto Repair |
| Sublet | Work the shop sends out to another business and bills to you. ASE's service consultant task list includes sublet procedures. Ask which lines are sublet and who warrants that work. | ASE C1 study guide |
| OEM part | A part from the carmaker, or made for it (original equipment manufacturer). The FTC says new parts come from carmakers and independent makers, and that prices and quality vary. | FTC, Auto Repair Basics |
| Aftermarket part | A new part made by a company other than the carmaker. California's collision rules require non-OEM crash parts to be identified as such on the estimate. | FTC, Auto Repair Basics; California BAR, Write It Right |
| Used (salvage) part | A part taken from another vehicle without alteration. The FTC says its reliability is seldom guaranteed. | FTC, Auto Repair Basics |
| Rebuilt, remanufactured, reconditioned | A used part restored for reuse. The FTC says the three words generally mean the same thing, and that the maker's warranty often covers the part but not the labor to install it. | FTC, Auto Repair Basics |
| Parts markup | The difference between what the shop pays for a part and what it charges you. ALLDATA, a repair-information vendor, describes consultants suggesting a 100 percent overall markup and a sliding scale by price. No source we found sets a legal limit. | ALLDATA, Proper Parts Pricing |
| Written estimate | The shop's written statement of the work, parts and labor it expects, before it starts. Whether one is required, and above what amount, depends on the state (table below). AAA advises against waiving one. | FTC, Auto Repair Basics; AAA, Insist on a Written Repair Estimate |
| Authorization | Your approval for specific work, up to an amount. Get it on paper, by text or by email; for a phone approval, write the date, time and the name of the person you spoke to, as California's rules require the shop to do. | California Business and Professions Code 9884.9; California BAR, Consumer's Guide to Auto Repair |
| Invoice, repair order | The final bill: each repair, the parts and their cost, labor, and the odometer reading in and out, in the FTC's and New York's lists. Match it to what you authorized. | FTC, Auto Repair Basics; New York DMV, Know Your Rights in Auto Repair |
| Repair warranty | The shop's own guarantee on its parts and labor. The FTC says there is no standard warranty on repairs, and California BAR says a shop is not required by law to guarantee its work; if it does, the terms should be in writing. | FTC, Auto Repair Basics; California BAR, Consumer's Guide to Auto Repair |
| Comeback | A car returned because a repair did not fix the problem or failed. ASE's service consultant task list includes handling them. | ASE C1 study guide |
| Mechanic's lien, garage keeper's lien | A shop's legal claim on the car for unpaid charges, which in some states lets it keep the car until paid. Michigan, Washington and California each set conditions; Washington's applies only within 110 percent of an authorized estimate. | Michigan Department of State, Repair facilities; Washington Attorney General, Auto Repair; California BAR, Write It Right |
| Storage fee | A daily charge for leaving the car at the shop. Florida requires it on the estimate form and allows none for three working days after the shop tells you the work is done; Massachusetts requires you to be told before you authorize. | Florida Statutes 559.905; Massachusetts Consumer Guide: Mechanics of Auto Repair |
Written estimates and charges over them: six state examples
These are examples of what six states require, read from each state's statute or agency page on 2026-11-01. They are not a summary of your state's law, and they change: Florida raised its threshold to $150 in 2024, and Michigan's margin took effect on February 1, 2026. Ask the authority
| State | When a written estimate is required | Charges over the estimate | Sources |
|---|---|---|---|
| California | Required for repairs (preventive maintenance at a posted price excepted). | None above the estimate without your consent, obtained before the extra work. | California Business and Professions Code 9884.9; California BAR, Write It Right |
| New York | Only if you ask for one. | The shop may not charge more than the estimate without your permission. | New York DMV, Know Your Rights in Auto Repair |
| Florida | When the repair will exceed $150, diagnosis included; you sign a choice of written estimate, a dollar limit or no estimate. | $10 or 10 percent, whichever is greater, but not over $50. | Florida Statutes 559.905; Florida Statutes 559.909 |
| Michigan | Before repair work; the state's page gives $50 or more. | 10 percent or $50, whichever is less (since February 1, 2026). | MCL 257.1332; Michigan Department of State, Repair facilities |
| Massachusetts | Before any work, signed by you, with listed exceptions. | The shop must ask before charging more than $10 above the estimate. | Massachusetts Consumer Guide: Mechanics of Auto Repair |
| Washington | Over $100, when you deal with the shop face to face. | Not more than 110 percent of the written estimate, sales tax excluded, without authorization. | RCW 46.71.015; RCW 46.71.025; Washington Attorney General, Auto Repair |
Your own state. Search for your state's name with "auto repair" and "attorney general" or "consumer protection"; the state's consumer agency or attorney general publishes the rule where one exists. USA.gov links each state's consumer protection office (USA.gov, state consumer protection offices) and says where to file complaints about a car (USA.gov, car complaints). Write what you find on the Car facts sheet beside the shop's details.
Limits
These definitions and examples help you read the paper and ask. They are not legal advice, and they do not say whether a charge on your bill is allowed. For a disputed bill, a lien or a car the shop is holding, the route is in Choosing a shop and handling problems: the manager, a written complaint, then your state's agency or attorney general, and a lawyer where needed.