Last Updated on September 25, 2026
Written by licensed insurance agent Andy walker
Reviewed by the Alias Insurance editorial team.
Yes, you should report any change that alters your car from its original factory specification if it could affect value, power, safety, theft risk, repair cost, or how you use the vehicle. Tell your insurer before the work starts when possible. If the work is already done, contact the insurer now and ask for written proof of any policy change.
Common reportable changes include engine tuning, turbochargers, engine swaps, suspension lifts or lowering kits, custom wheels, body kits, wraps, custom paint, upgraded audio gear, altered lighting, wheelchair lifts, hand controls, roll cages, and changes made for racing, off-road driving, rideshare, or business use. A dealer-installed option may also count if it was not part of the model’s standard factory equipment.
A standard auto policy may insure only the car’s stock value or provide a small limit for added equipment. It may not pay the full cost of custom parts after theft, fire, vandalism, or a crash. An insurer may add a custom parts endorsement, request receipts or photos, adjust the premium, place limits on certain parts, or refer the vehicle to a specialty policy. Terms differ by insurer and state.
Do not assume a legal part is insured, or that an insured part is legal for street use. Federal emissions rules and state laws on tint, lighting, noise, ride height, and equipment still apply. Your declarations page, endorsements, and full policy control any claim. Ask a licensed agent or insurer to confirm coverage in writing.
What counts as a modified car?
A modified car has equipment, software, body work, or a use that differs from the condition in which the maker supplied that trim. Insurers may use terms such as modification, customization, accessory, custom part, aftermarket equipment, or alteration. Each policy can define those terms in its own way.
SEMA reported $51.8 billion in U.S. specialty equipment sales during 2022. Half of vehicle modifiers were under age 40. A stock value may not capture all added gear.
New brake pads, a battery, or maker-approved tires are often upkeep, not custom work. Oversized tires and a lift are different because they alter size and handling.
If you are unsure, send the insurer a short description and ask. A written answer is more useful than guessing.
Which car modifications must you report?
Report a change if it affects at least one of these five factors:
- The car’s replacement or repair cost
- Engine power, acceleration, braking, steering, or handling
- Theft or vandalism risk
- Required safety or emissions equipment
- The way, place, or purpose for which you drive
Use this table as a quick check. Your policy still controls.
| Modification or change | Report it? | Why the insurer may ask |
| ECU tune, performance chip, turbo, or supercharger | Yes | It may raise power, part cost, and mechanical risk |
| Engine or transmission swap | Yes | It changes core specifications, value, and repair needs |
| Exhaust or emissions system change | Yes | It may affect value, legality, noise, and emissions compliance |
| Lowering springs, coilovers, or lift kit | Yes | It can change handling, ground clearance, and repair cost |
| Nonstandard wheels or tires | Yes | Size, value, theft risk, and handling may change |
| Upgraded brakes | Yes | The parts add value and may alter vehicle performance |
| Body kit, spoiler, hood, or custom bumper | Yes | Custom panels can cost more to source and repair |
| Custom paint, vinyl wrap, or graphics | Yes | The finish adds cost and may need special repair work |
| Audio, video, or navigation equipment | Yes | High-value electronics can raise theft and replacement cost |
| Custom seats, steering wheel, harness, or roll cage | Yes | These parts may affect occupant safety and intended use |
| Window tint or altered lights | Yes | State equipment rules vary, and replacement cost may change |
| Alarm, immobilizer, tracker, or dash camera | Ask | Some insurers record security gear or offer a discount |
| Hand controls, pedal extensions, ramp, or wheelchair lift | Yes | Adaptive equipment adds value and may need special coverage |
| Trailer hitch, roof tent, plow, or permanent rack | Ask | Weight, use, and added equipment can affect the risk |
| Ordinary replacement part matching factory specifications | Usually no | It is often maintenance, but policy definitions still govern |
| Racing, timed events, rideshare, delivery, or business use | Yes | A use change can create an exclusion or require another policy |
A shop cannot decide what your policy covers.
Why do insurers need to know about modifications?
Insurers price and insure the risk described in the application and policy. A change may affect several parts of that risk.
- A body kit, custom paint blend, or imported wheel may cost more to fix than a stock part.
- A stock value tool may miss an engine build, audio system, mobility conversion, or other added gear.
- More power, a lift, new tire sizes, or a low ride height can change how the car acts.
- Wheels and visible audio or speed parts may affect theft risk.
- A show car, track car, daily car, and delivery car each has a different use.
The NAIC says an insurer may base a total loss on what the car was worth just before the crash. It also tells owners to research the value on their own.[2] Policy terms may still limit how added parts count.
A new car can also have nonfactory parts. A dealer may add a lift, wheels, wrap, or audio gear before sale. Keep the buyer’s order and ask if each add-on is covered. See how make and model can affect insurance rates for more context.
When should you tell your insurance company?
Call before you buy or install a costly part. Ask if the firm accepts it, what coverage it offers, and which records it needs.
Give the firm a parts list, costs, and the planned use. Ask about limits, deductibles, exclusions, photos, bills, and appraisals. Get any new policy page or endorsement in writing. Check it after the work and at each renewal.
If the work is complete, disclose it now. Give the installation date and state whether the car’s use changed. Do not wait for renewal or a claim.
How can a modification change your coverage?
One insurer may accept mild suspension work. Another may require added parts coverage. A third may decline a tuned engine or track use. State rules and company guides shape the result.
| Possible insurer response | What it may mean for you |
| No policy change | The company records the change but keeps current terms |
| Added equipment endorsement | A listed limit covers approved custom parts after a covered loss |
| Higher or lower premium | The insurer changes the price based on added risk or an accepted safety feature |
| New deductible or limit | Certain equipment may have separate claim terms |
| Photos, receipts, or appraisal required | The company wants proof of ownership, condition, and value |
| Specialty or collector policy | The vehicle may need agreed usage, storage, mileage, or valuation terms |
| Coverage restriction or refusal | The company will not insure a part, use, or build under its rules |
Physical damage coverage matters here. Liability insurance pays for covered injury or damage you cause to others, up to policy limits. It does not repair your own custom parts. Collision coverage may pay for covered crash damage to your car. Other-than-collision coverage may address covered theft, fire, vandalism, falling objects, or weather losses. Read the car insurance coverage guide and the details on collision car insurance before choosing limits.
An added equipment endorsement usually works only with the underlying covered cause of loss. It does not turn routine wear, poor installation, or a mechanical failure into an insured event unless the policy says so.
What value terms should you compare?
Policies for altered cars may use different value methods. Similar labels can lead to different payouts, so read the loss clause.
Actual cash value
Actual cash value often reflects the car’s value just before the loss. Age, condition, miles, local prices, and listed equipment may count. A part’s cost does not prove that it added the same sum to resale value.
Stated amount
A stated amount is often a cap used for the rate or claim. Some forms pay the least of that amount, actual cash value, or repair cost. Do not treat the number on the policy page as a set total-loss payout without reading the form.
Agreed value
An agreed-value policy sets a sum that both sides accept, subject to the contract. It may fit some show cars or cars with major work. It may also limit miles, drivers, storage, or daily use.
Ask the insurer to show, in the policy, how each custom part will be valued. If the insurer requires an appraisal, use a qualified appraiser who understands the type of build.
What happens if you do not report a modification?
The outcome depends on the policy, facts, state law, and connection between the missing information and the claim. Possible results include:
- No payment for the custom part above the policy’s included limit
- Payment based on stock equipment rather than the upgraded part
- More investigation and a slower claim
- A corrected premium or changed terms
- Claim denial if an exclusion or material misstatement applies
- Cancellation, nonrenewal, or rescission where the contract and state law allow it
None of these outcomes is automatic in every case. Still, hiding a change creates avoidable risk. The NAIC urges consumers to complete insurance applications accurately and keep a copy. A claim is a poor time to learn that the insurer never agreed to cover a $6,000 sound system or a swapped engine.
Consider three cases. A $4,000 wheel set is stolen, but the policy has a small limit for added gear. Receipts prove the purchase, yet they do not raise that limit. Another driver lists hand controls and a wheelchair lift on an endorsement. That written record helps the insurer review a later covered claim. NHTSA says owners should work with trained mobility experts and keep insurance while a car is at a shop for such work. A third driver adds a roll cage and starts timed events. The driver must report both the cage and the new use, then check for a racing exclusion.
Are all car modifications legal?
No. Insurance approval does not replace federal, state, or local law. A modification can be insurable yet illegal for road use, or legal yet outside a carrier’s underwriting rules.
Federal law bars tampering with required vehicle emissions controls and bars making, selling, or installing aftermarket devices intended to defeat them. EPA states that known defeat-device sales for certain diesel trucks from after 2009 through 2020 caused an estimated 570,000 tons of excess nitrogen oxides and 5,000 tons of excess particulate matter over those trucks’ lives.
State rules may govern:
- Window tint darkness and reflectivity
- Headlight, taillight, and underbody light colors
- Exhaust sound and mufflers
- Bumper and frame height
- Tire coverage beyond the fender
- License plate visibility
- Safety inspections and emissions tests
- Vehicle title or registration changes after major reconstruction
Check your state DMV, environmental agency, and insurance department before installation. Keep inspection or emissions records. A part advertised for off-road use may not be lawful on public streets.
How should you document a modified car?
Good records help the insurer check value and claims. Save:
- Dated receipts for parts and labor
- Before and after photos from each side
- Installer invoices and certifications
- Appraisals and valuation updates
- Emails or letters sent to the insurer
- Revised declarations pages and endorsements
- Inspection and emissions records
Take photos in clear light. Store copies away from the car. Tell the insurer after each stage of a long build. An old appraisal may not reflect new work or a new market value.
How can you compare insurance for a modified car?
Price matters, but the lowest quote can leave the largest gap. Give each licensed agent or insurer the same parts list and use description. Then compare answers in writing.
Ask these key questions:
- Which changes and parts does the quote accept?
- What limit and deductible apply to added gear?
- How will the firm settle a partial loss or total loss?
- Are track, show, off-road, daily, or work uses barred?
- Does coverage apply at a shop and in transit?
- What photos, bills, appraisals, or checks are due?
Compare the declarations page, endorsement, exclusions, and valuation clause, not just a sales summary. Progressive, for example, says modified vehicles may need an endorsement or separate custom-car policy and warns that custom parts may not be covered if the insurer was not told. That is one carrier’s guidance, not a rule for every policy.
How can different drivers manage the cost?
Young or high-risk drivers may face a high base rate before added parts enter the quote. A driver on a tight budget may not insure each style upgrade. A senior or driver with a disability may need to protect costly aids. These steps can help:
- Ask for a quote before buying each high-cost part.
- Choose a deductible you could pay after a loss.
- Compare the cost of an endorsement with the amount it adds.
- Use anti-theft gear accepted by the insurer.
- Review annual mileage and use honestly.
Dropping damage coverage can cut the rate, but it leaves your car at risk. A loan or lease may require it. Check the contract and your savings before removing it.
What should you do before your next modification?
Use this short checklist:
- Write down the exact part, labor cost, and planned use.
- Check federal, state, and local equipment rules.
- Call the insurer before installation.
- Ask for written acceptance and coverage terms.
- Save receipts, photos, and installer records.
- Check the new declarations page and endorsements.
- Review the policy again after each renewal.
If the insurer will not cover the build, compare specialty carriers before canceling the current policy. Avoid any gap in required liability coverage. Minimum insurance laws differ by state, and a lender may demand more coverage than state law.
Frequently Asked Questions
Yes, report custom paint, wraps, body kits, spoilers, wheels, lights, and interior changes. Cosmetic parts can raise repair cost, theft risk, or vehicle value. Ask whether the standard policy includes any added-equipment limit and whether you need an endorsement.
No. A change may raise the price, lower it, or leave it unchanged. Added power and costly parts can increase risk. An accepted alarm or immobilizer may qualify for a discount with some insurers. The company, state, vehicle, driver record, and modification all matter.
Only if the policy and insurer accept the change and the cause of loss is covered. A custom-parts endorsement may protect the equipment from covered crash or theft damage. It normally does not pay for wear, bad workmanship, or engine failure by itself.
They can be. Custom parts may cost more to replace, and performance changes may alter underwriting risk. Some mild changes have little effect. A specialty policy may cost more or less than a standard policy depending on value, mileage, storage, use, and driver history.
It may deny or limit a claim if policy wording, an exclusion, an uncovered part, or a material misstatement applies. The result depends on the loss and state law. An undeclared change does not create the same outcome in every claim. Give accurate information and keep written proof of coverage.
An insurer may treat a permanently installed camera as added electronic equipment. A removable camera may be handled differently. Report a costly or hardwired unit and ask whether theft or damage is covered. Save the receipt and check whether stored footage has privacy rules in your state.
Protect the car you actually own
The safest rule is simple: report any nonfactory change that affects value, performance, safety, theft exposure, repair work, or vehicle use. Do it before installation when you can. Keep records, read the endorsement, and confirm the loss-settlement method. State laws and policy terms vary, so use official state sources and a licensed insurance professional for advice about your car. Alias Insurance can help you compare the questions that matter without treating a low price as proof that custom parts are covered.
Sources and References
