Shop Supplies Fee in Auto Repair: Rules and Rates

A shop supplies fee in auto repair is the line on an invoice that covers the small consumables used on a job: shop towels, brake cleaner, penetrating oil, wire ties, thread locker, gloves. They're real costs, but itemizing a squirt of brake cleaner on every repair order isn't practical, so most shops charge a small fee instead.

More on this topic: Pricing and shop numbers, every guide in one place.

It's also one of the most questioned lines on a bill, and in some states it's tightly regulated. This guide covers what the fee should cover, how to set the rate from your own numbers, the state rules we could verify, and how to explain it so it doesn't cost you trust.

The short answer

A shop supplies fee, in short, covers consumables that can't be itemized per job, such as cleaners, rags and lubricants. Shops usually charge a flat fee or a percentage of labor, ideally with a dollar cap, disclosed before work. Check your state first: California bans a generic shop supplies line, while Florida and Maine set disclosure rules.

Key takeaways

• Set the rate from your own costs: last quarter's consumables spend divided by labor sold gives you a percentage that's defensible.
• Cap it in dollars so a big job doesn't carry a supplies charge nobody can explain.
• Bill anything you can measure per job (fluids, hardware, gaskets) as parts, not as "supplies".
• California prohibits a generic shop supplies charge; Florida requires a specific statement on the estimate; Maine requires a posted notice and a single line item.
• Some states tax the fee. Virginia has taxed separately stated supplies charges since July 1, 2017.

Disclosure: we make BayRobin, an AI receptionist and front office for independent repair shops, and show where it fits. Everything here works without it. Figures from other companies come from their public pages, checked in October 2026 and linked at the end.

What is a shop supplies fee?

It's a charge for consumables used during a repair that aren't worth itemizing. AAA's guide to repair bills explains it to drivers this way: "Some repair shops charge a flat fee for shop supplies, while others itemize the fee." Virginia's tax department, in a 2017 bulletin, describes the fee as "typically a flat-fee or a percentage of the total amount charged by the shop for the repair."

Customers mostly accept it when it's small, disclosed and consistent. They push back when it appears without warning, when it's large on a job that clearly used few supplies, or when it looks like a percentage of the parts bill.

What should a shop supplies fee cover, and what shouldn't it?

If you can count it or measure it, put it on the repair order as a part. That keeps the supplies fee small, which is exactly what makes it easy to defend.

How do shops calculate a shop supplies fee?

Percentage of labor with a dollar cap is the easiest to justify, because supplies are used while technicians work, not when you buy parts. The percentages and caps above are examples, not benchmarks: there's no reliable public survey of what shops charge, so set yours from your own costs.

How do you work out the right percentage for your shop?

1. Add up last quarter's consumables purchases: cleaners, towels or towel service, lubricants, gloves, ties, covers. Leave out anything you already bill as parts.
2. Add up labor sold in the same quarter.
3. Divide consumables by labor sold. That's your cost percentage.
4. Decide whether the fee should only recover cost or carry a margin like your parts do, and round to a number your service writers can say easily.
5. Look at your largest repair orders and set a dollar cap so no single job carries a supplies charge you'd be embarrassed to explain.

Worked example (illustrative numbers)

A four-bay shop spends $3,100 on consumables in a quarter and sells $96,000 of labor. $3,100 ÷ $96,000 = 3.2%. The owner rounds to 4% of labor to cover handling, with a $35 cap. A brake job with $280 of labor gets $11.20; a timing belt with $900 of labor would be $36, so it's capped at $35; a $60-labor oil change gets $2.40. Each charge tracks the work, and the quarterly total roughly matches what the shop actually spent.

Re-run the math once a year. If your consumables cost falls (a cheaper towel service, say), lower the rate. That's a better story than a fee that only ever goes up.

What are the state rules on shop supplies charges?

Rules differ a lot between states. The ones we read in the statutes and regulations themselves:

California also lets shops itemize hazardous waste disposal separately, with the shop's EPA ID number on the estimate and invoice. Many states have no rule specific to supplies but do require that every charge appear on the estimate the customer authorizes. This isn't legal advice; check your state's repair-shop rules and your state tax department before setting the fee.

Is the shop supplies fee taxable?

It depends on the state. Virginia's 2017 bulletin is an example of a state that taxes a separately stated supplies charge. Other states treat it differently, and the answer can change depending on whether the fee is itemized or folded into labor. Ask your accountant or your state's tax department; it's a five-minute question that avoids an audit finding.

How do you explain the shop supplies fee to customers?

Disclose it before work, on the estimate, and have a plain sentence ready:

"That line covers the cleaners, lubricants and towels the technician uses on your car. It's 4% of the labor, and it never goes over $35."

If a customer objects on a small job, the fee isn't worth the argument; your service writer can waive it within a limit you set, and note why. If objections are frequent, consider the alternative below.

Should you drop the fee and raise your labor rate instead?

Some shops fold supplies into the labor rate and drop the line entirely. The bill looks cleaner and there's nothing to argue about, but your posted rate rises, and that's the number price shoppers compare. If you go this way, raise the rate by your consumables percentage, not a round guess, and check the result against your effective labor rate. In California, a generic supplies line isn't an option anyway, so this or full itemization is the route.

Frequently asked questions

What percentage do auto repair shops charge for shop supplies?

There's no reliable public benchmark. Shops typically use a flat fee or a percentage, often of labor, with a dollar cap. Set yours from your own numbers: last quarter's consumables spend divided by labor sold, rounded, with a cap for large jobs.

Is a shop supplies fee legal?

In most states, yes, if it's disclosed before work and appears on the estimate the customer authorizes. California prohibits charging for items generally noted as shop supplies; supplies used on the vehicle must be in the estimate and itemized on the invoice. Florida and Maine set specific disclosure rules.

Should the shop supplies fee be a percentage of parts or labor?

Labor is easier to justify, because supplies are used while technicians work, not when parts are bought. A percentage of parts makes the fee jump on jobs with expensive parts but little labor, which is what customers question most.

Do I have to charge sales tax on shop supplies?

It depends on your state. Virginia, for example, has taxed separately stated shop supplies charges since July 1, 2017. Check with your accountant or state tax department.

Can a customer refuse to pay a shop supplies fee?

If it was disclosed on the estimate and authorized, it's part of the agreed price. If it wasn't disclosed, you'll have a hard time defending it, and in some states you may not be allowed to charge it. Disclose it up front to avoid the argument.

Where BayRobin fits

In BayRobin, a repair order is made of labor, parts and fees, so a supplies fee sits on the estimate the customer approves on one link, and on the invoice they pay by text. Set it the way your state allows, from the price book on every plan. BayRobin is free until your first 10 booked jobs, no card up front. Start free or see pricing.

Related: should your shop charge a diagnostic fee, how to write an auto repair estimate, how to set your labor rate, price book and maintenance plans.

Sources

Competitor details in this post were checked against these public pages in October 2026. Products and prices change, so confirm with each vendor before you decide.

• California Bureau of Automotive Repair: Write It Right
• California 16 CCR 3356: invoice requirements (Cornell LII)
• Florida Statutes 559.905 (2025): written repair estimates
• Maine P.L. 2005, ch. 189 (LD 831): shop supplies billing
• Virginia Tax Bulletin 17-7: shop supplies charges
• AAA Club Alliance: Understand your auto repair bill