Who we serve / Auto repair
Estimates and invoices for auto repair shops, with the customer's yes on the record.
In a repair shop, the estimate is not a formality. Several states say the shop may not go over it without the customer's approval, and some say how that approval is recorded. Here is how to keep it simple.
By Abrar · Updated · 8 min read
Free plan available. No credit card for Free.
The short answer
Auto repair has more written rules than most trades. Give a written estimate with parts and labor. Get the customer's approval before extra work, and record when and how they gave it. Say what happens with old parts and storage. Itemize parts and labor on the invoice. InvoiceWren keeps the estimate, each approved change and the payment on one job, with a record of the approval.
How a repair job runs on paper
Most customers are not there for the work. They are there to find out the price. The paper below is how that price stays the price.
- 1
The call or the drop-off
A customer brings in a car with a symptom. Write down who owns it, the car, the mileage and what they say is wrong. Many shops also write down what the customer wants done and what they do not.
- 2
The check-in and the diagnosis
Look at the car and find the cause. Write down what you found. Find out and say whether there is a charge for the diagnosis if the customer has the work done elsewhere; the Federal Trade Commission tells customers to ask [1].
- 3
The written estimate
Parts and labor for the specific job. In New York, a repair shop must give the customer a written estimate of the parts and labor for each specific repair if they ask for it [2]. Florida requires a written estimate when the repair will cost more than $150, unless the customer waives it in writing [3].
- 4
The authorization
The customer approves the estimate. California says authorization can be written, oral or electronic, such as an email or a text [4]. Record how and when it was given.
- 5
The repair
Do the work that was approved. Do not start storage charges while approved repairs are in progress: California says storage cannot be charged until a lien has arisen [5].
- 6
The extra work
You find more wrong. Before you do it, California requires a revised work order and the customer's authorization, by phone, email, text or other electronic means, recorded on the work order and the invoice [6]. New York says the shop may not charge more than the estimated price without the customer's permission [2].
- 7
The invoice
It lists each repair, each part and its cost, and the labor. Florida also requires the date, the odometer reading and whether parts are new, used or rebuilt [7]. California requires the shop's registration number [6].
- 8
The pick-up and the payment
Hand back the old parts if the customer asked for them. Record the payment and give a receipt.
Where auto repair paperwork goes wrong
Each is a dispute over the bill, and most are covered by written state rules.
Extra work approved by a phone call nobody wrote down
You find more wrong, call the customer, and they say yes. At the counter they say they never did. California requires a revised work order and authorization before additional repairs, and the authorization recorded on the work order and the invoice [6].
What to do: Write what you were told and when, the same minute. A revised estimate with the added parts, labor and new total is the record.
A final bill above the estimate
New York says the shop may not charge more than the estimated price without the customer's permission [2]. Florida's estimate form says the shop may not exceed the amount without the customer's written or oral approval [3].
What to do: Keep the estimate on one page, and list every addition separately, with the customer's yes beside it.
An estimate that was only spoken
A Texas legal aid page notes that Texas has no laws that specifically apply to auto repair shops, and warns of shops that give a verbal estimate and then a bill far beyond it [8]. That is a reason customers distrust any shop that does not write it down. Florida requires a written estimate over $150 [3].
What to do: Write every estimate, even where no state requires it.
Storage fees and a car left on the lot
California says a shop can charge reasonable storage fees after a lien has arisen, and that towing authorization must be on a form separate from the repair estimate [5]. In Texas, a mechanic has the legal right to keep the car until the customer pays [8].
What to do: Say on the estimate what storage fees apply and when they start. Tell the customer the day the car is ready.
Old parts asked for too late
California says the shop must return replaced parts if the customer asks when the estimate is authorized [6]. New York says the customer is entitled to the return of replaced parts, except warranty and exchange parts [2].
What to do: Put a "return my old parts" line on the estimate, for the customer to tick or not.
Parts and labor on one lump line
California says to list parts and labor separately on an invoice, and that charges for labor and services are generally not taxable [9]. Texas says repair labor is not taxable, and that if the parts and labor are itemized the shop must collect sales tax on the parts. A lump sum shifts the tax to what the shop pays its own suppliers [10].
What to do: Show parts and labor on separate lines every time. Ask your state tax office how your state treats each.
What InvoiceWren does for an auto repair shop
The customer's approval is recorded with a name and a time, on your phone or the counter tablet.
An estimate with parts and labor on separate lines
Add each part and the labor as their own lines, with the diagnosis. Your customer reads it on their phone and signs it there, so the approval has a name and a time.
Saved items for the parts and jobs you quote every day
Save "brake pads and rotors, front", "oil and filter" and "diagnostic fee". The next estimate takes a tap per line.
Photos on the line they belong to
Add up to 3 photos to a line. The worn rotor sits beside its price.
Change orders for added work
Found more wrong? Send a change order with the added parts, labor and the new total. The customer approves it on their phone before you start, and it is not counted as approved until they do.
One job, one balance
The final invoice shows the estimate, each approved change and each payment, line by line, so the bill matches what was approved.
Paid by Zelle, bank transfer or your own link
Your customer pays you directly and we take no fee. They tap "I've paid", you check your account and confirm, and the receipt goes out.
Reminders that stop when they pay
If a bill is not paid when the car is ready, InvoiceWren emails your customer for you. You set the schedule, and it stops once you confirm the payment.
Estimates and approval · Change orders · Deposits, progress and final invoices · Getting paid and receipts
Need a document right now? Make a free estimate or a free invoice with no sign-up, then bring the job into InvoiceWren when you are ready.
Rules to check, by state
Auto repair is regulated by the states, and the rules are not the same. These are examples from official pages we read on Nov 13 2026, and one legal-aid page for Texas. They are not every rule. Check yours.
- California: before any additional repairs beyond the estimate, the shop needs a revised work order and the customer's authorization by phone, email, text or other electronic means, recorded on the work order and the invoice. The invoice shows the shop's registration number. Replaced parts are returned if the customer asks at the time the estimate is authorized [6].
- California: a repair dealer can charge reasonable storage fees after a lien has arisen. Towing authorization is on a form separate from the repair estimate [5]. Authorization can be written, oral or electronic [4].
- Florida: a written estimate is required when the repair will cost more than $150, unless the customer waives it in writing. The estimate form says the shop may not exceed the amount without the customer's written or oral approval [3]. The invoice includes the date, the odometer reading, the description of the work, itemized labor and parts, whether parts are used, rebuilt or reconditioned, and the guarantee [7].
- New York: on request, the shop must give a written estimate of the parts and labor for each specific repair. It may not charge more than the estimate without the customer's permission, and the customer is entitled to the return of replaced parts except warranty and exchange parts [2].
- Texas: a legal-aid page, not a regulator, says Texas has no laws that specifically apply to auto repair shops, that general consumer protection law applies, and that a mechanic has the right to keep the car until the customer pays [8].
- Sales tax: California says charges for labor and services are generally not taxable, and invoices should list parts and labor separately [9]. Texas says repair labor is not taxable, and that if the parts and labor are itemized the shop must collect sales tax on the parts [10].
This is general information, not legal or tax advice.
Checklist
Questions
Do I have to give a written estimate?
It depends on the state. Florida requires one when the repair will cost more than $150, unless the customer waives it in writing [3]. New York requires one for each specific repair if the customer asks for it [2]. Writing every estimate is the safest habit.
How do I record the customer's approval of extra work?
California says authorization can be written, oral or electronic, and it has to be recorded on the work order and the invoice [6][4]. In InvoiceWren you send a change order, and the customer approves it on their phone, so the approval has a time.
Can the final bill be higher than the estimate?
Not without the customer's permission in states such as New York [2] and Florida [3]. Write each addition separately with the customer's yes.
Do I have to give back the old parts?
In California, if the customer asks when the estimate is authorized [6]. In New York, the customer is entitled to the return of replaced parts except warranty and exchange parts [2]. A tick-box on the estimate settles it.
When can I charge storage?
California says reasonable storage fees can be charged after a lien has arisen [5]. Say on the estimate what storage fees apply and when they start.
What must an invoice show?
It depends on the state. Florida lists the date, the odometer reading, a description of the work, itemized labor and parts, whether parts are used or rebuilt, and the guarantee [7]. California requires the shop's registration number [6]. New York lists each repair, each part and its cost [2].
Do I charge sales tax on repairs?
It depends on the state. California generally does not tax charges for labor and services, and says to list parts and labor separately [9]. Texas does not tax repair labor, but taxes itemized parts [10]. Ask your tax office.
Can I keep the car until the customer pays?
In Texas, a legal-aid page says a mechanic has the legal right to keep the car until the customer pays for the repairs [8]. Other states have their own lien rules, so ask yours.
Send your next estimate from the job.
Free plan available. No credit card for Free.
Sources
- Federal Trade Commission: Auto Repair Basics. Checked .
- New York State DMV: Know your rights, auto repair. Checked .
- Florida Statutes 2025, section 559.905: Motor Vehicle Repair estimates. Checked .
- California Bureau of Automotive Repair: Maintenance and repairs, consumer page. Checked .
- California Bureau of Automotive Repair: Automotive repair dealers and storage fees. Checked .
- California Bureau of Automotive Repair: Write It Right, documentation and authorization requirements. Checked .
- Florida Statutes 2024, section 559.911: Invoices. Checked .
- TexasLawHelp.org, Texas RioGrande Legal Aid (a legal-aid page, not a government page): Car Repair. Checked .
- California Department of Tax and Fee Administration: Auto Repair Garages, industry topics. Checked .
- Texas Comptroller: Motor Vehicle Repairs, Remodels and Maintenance (publication 94-113). Checked .
Prices and features change. We check these pages before each update. If something here is out of date, tell us at hello@invoicewren.com and we will fix it.