How to File a Claim With the At-Fault Driver’s Insurance Company: A 2026 Step-by-Step Guide

Here is the short answer: you file a third-party liability claim — you call the at-fault driver’s insurer directly, report the crash, prove the other driver caused it, document every dollar of your damages, and negotiate a settlement. The full process has nine steps: gather your documentation, notify insurers promptly, identify the at-fault driver’s insurer, make the first call carefully, bridge the investigation gap, document your damages continuously, evaluate the settlement offer, negotiate from a position of paper, and escalate if the claim is denied. Each section below walks you through one of these steps in detail.

After a car accident that was not your fault, you have a right most victims never fully use: you can claim directly against the insurance policy of the driver who caused the crash. If you are wondering how to file a claim with the at-fault driver’s insurance company, this guide walks you through every step — from gathering evidence and making the first phone call, to surviving the investigation period, evaluating a settlement offer, and escalating the claim if the insurer denies it.

This is the complete, practical filing process that other guides leave out: what to say, what never to sign, which deadlines matter, and how the rules change depending on the state you live in.

What Is a Third-Party Claim, and Why Does It Matter?

When you file against your own policy, that is called a first-party claim. When you file against the other driver’s policy, it is called a third-party claim — you are a third party claiming against their contract, not yours.

The distinction matters enormously, because the at-fault driver’s insurer is not on your side. Your own insurer owes you contractual duties (and can face bad-faith penalties if it mistreats you). The other driver’s insurer owes you nothing except what the law requires it to pay its own policyholder’s victims — and it will protect its money accordingly.

In fault-based (tort) states, you must prove the other driver was at fault before their insurer pays a penny. Police reports and witness statements are the backbone of that proof.

In no-fault or personal-injury-protection (PIP) states, your own policy pays your initial medical costs regardless of who caused the crash, and you can only pursue the at-fault driver’s insurer for serious injuries that cross the state’s tort threshold. Understanding which system your state uses is the single most important thing to get right before you start. The table below summarises the difference.

FEATURE	THIRD-PARTY CLAIM (THEIR INSURER)	FIRST-PARTY CLAIM (YOUR INSURER)
Who pays	The at-fault driver’s liability coverage	Your collision, medical-payments (MedPay), or PIP coverage
Fault requirement	You must prove the other driver caused the crash	Generally no fault proof needed (except in liability disputes under your own uninsured-motorist coverage)
Duty owed to you	None — the insurer’s client is the other driver	Contractual duty of good faith toward you
Deductible	Usually none — you pay nothing out of pocket	Your deductible applies (e.g. $500–$1,000)
Recorded statement	You can decline or have a lawyer present; it is a trap	Your policy may require cooperation
Rental car during investigation	Owed only after liability is accepted — a painful gap	Covered immediately if you carry rental-reimbursement coverage
Typical timeline	30–90 days for property damage; months for injury claims	Often faster, especially for vehicle repairs

Step 1: Gather Your Documentation Before You Call

The strength of a third-party claim is almost entirely determined by the quality of its paperwork. Insurers do not pay on stories; they pay on documented, verifiable losses.

Assemble the following file — physical or digital — before you contact the at-fault driver’s insurer, because everything you say on that first call should be backed by something you can point to:

Police report (and the report number). This is the single most persuasive document in a fault dispute. If officers responded to the scene, obtain the report from the department or its online portal — it usually becomes available within 5–10 business days. If no officer attended, file a report yourself as soon as possible; a self-filed report is weaker but far better than none.
Photos and video. Vehicle damage from multiple angles, the crash scene, skid marks, traffic signals, road conditions, and your visible injuries (photographed over several days as bruising develops). Do not rely on memory — download dashcam footage immediately before it is overwritten.
Medical records and bills. Every emergency-room visit, doctor’s appointment, physiotherapy session, prescription, and scan — with itemised bills, not just receipts. Gaps in treatment are the number-one reason insurers discount injury claims, so keep appointments continuous and keep every record.
Receipts for every out-of-pocket expense. Towing, ambulance co-pays, medications, medical equipment, child care while you were at appointments, parking at the hospital — all of it. Small amounts add up, and insurers will not reimburse what you cannot document.
Wage-loss proof. A letter from your employer confirming your role, pay rate, and the hours or days missed, plus recent pay stubs. If you are self-employed, gather tax returns, invoices, and bank statements showing the income you lost — this takes more work but is fully claimable.
Witness information. Names, phone numbers, and written statements (even brief ones) from anyone who saw the crash. Independent witnesses are devastating to an insurer’s “disputed liability” defence, and memories fade fast — contact witnesses within days, not months.
The at-fault driver’s details. Name, licence-plate number, driver’s licence number, vehicle make/model, and — crucially — their insurance company name and policy number, which should be on the police report or the information exchanged at the scene.

Organise all of this into one labelled folder. When the adjuster asks “do you have documentation for that?”, the answer should always be “yes — I can send it today.”

Step 2: Notify Insurers Promptly — Including Your Own

Most insurance policies contain a prompt-notice clause: you must report a claim within a reasonable time, and many policies define that as days, not weeks. Even though your target is the at-fault driver’s insurer, you should also notify your own insurer immediately.

This is not disloyalty — it is protection. Your own policy’s collision, MedPay, or uninsured/underinsured-motorist coverage may become essential if the other driver turns out to be uninsured, underinsured, or uncooperative. Failing to notify your own carrier promptly can give it grounds to deny your first-party coverage later, when you need it most.

Separately, understand the two deadlines that can destroy an otherwise valid claim:

The statute of limitations. Every state sets a hard deadline for filing a personal-injury lawsuit — commonly two or three years from the crash date (for example, two years in Texas and Florida, three years in New York). Miss it and you lose the right to sue, which also destroys your settlement leverage. Property-damage deadlines are sometimes longer, but never assume.
The insurer’s internal timeline. Once you file, the insurer must acknowledge, investigate, and decide on your claim within timeframes set by state insurance regulations — often 30 days to accept or deny after receiving proof of loss, with extensions for complex investigations. Knowing these deadlines lets you hold the adjuster accountable; read our guide on how long an insurance company has to settle a claim to see the rules that apply to you.

Delay hurts you in a third, subtler way: it gives the insurer ammunition. A two-week gap between the crash and your first doctor’s visit will be framed as “the injury wasn’t serious” or “something else caused it.” Prompt action is both a legal safeguard and a negotiating advantage.

Step 3: Identify the At-Fault Driver’s Insurance Company

In a cooperative world, the other driver hands you their insurance card at the scene. In the real world, drivers flee, refuse, or claim they “left the card at home.” You are not stuck. The police report is your primary tool — responding officers routinely record insurance details. If there is no police report, you can still file: you need the driver’s name, licence-plate number, and vehicle description, and the insurer can be identified through the state’s department of motor vehicles or insurance database. Many states also let you request the registered owner’s insurance information directly from the DMV with a permissible purpose.

What if the at-fault driver is uncooperative?

File the claim anyway using whatever you have — plate number, vehicle details, and the police report number are usually enough for the insurer to locate its policyholder. Simultaneously, activate your own safety net: your collision coverage pays for your vehicle repairs regardless of fault, and your uninsured-motorist coverage steps in if the other driver has no insurance at all. Your insurer can then subrogate — pursue the at-fault driver or their insurer to recover what it paid you. If their limits turn out to be too low for your damages, your underinsured-motorist coverage may cover the gap. Never let an uncooperative driver stall you into missing deadlines.

Step 4: Make the First Call — What to Say and What Never to Say

Call the at-fault driver’s insurer’s claims department (the number is on their website — search “[insurer name] file a claim”). You will be assigned a claim number and an adjuster. This call sets the tone for everything that follows, so treat it as a formal proceeding, not a casual chat. Here is a script that works:

“Hello, I’d like to open a third-party liability claim. My name is [your name], the accident happened on [date] at [location], and your policyholder [driver name, policy number if known] struck my vehicle. The police report number is [number]. I’d like a claim number and the name and direct contact details of the adjuster assigned to my file. Please confirm the best email address to send documentation.”

Stick to facts: date, location, vehicles involved, police report number. Then stop. The adjuster may sound warm and helpful — that is their job, and it is also their strategy. Protect yourself with these rules:

Do not give a recorded statement on the first call. You are not legally required to give one to the other driver’s insurer. Recorded statements exist so the insurer can find inconsistencies later. Politely decline: “I’m not prepared to give a recorded statement today. I’ll provide a written account with my documentation.” If you eventually agree, have an attorney review the strategy first.
Never speculate about fault or injuries. Do not say “I’m fine” (soft-tissue injuries often surface days later), do not say “I think the light was…” and never apologise — apologies get quoted back as admissions.
Do not sign anything yet. The adjuster may send a medical authorisation form “so we can verify your treatment.” Blanket authorisations let them dig through your entire medical history looking for pre-existing conditions. Provide records yourself, on your terms.
Do not accept a quick settlement offer. Early offers — sometimes within days — are designed to close the file before you know the full extent of your injuries and costs. Never settle until your treatment is complete or a doctor has given a final prognosis.
Keep everything in writing from here on. After the call, confirm key points by email. If the adjuster promises a rental car or a callback date, get it in an email. Phone promises evaporate; written ones create a paper trail.

Step 5: Survive the Investigation Gap

Here is the part nobody warns you about. After you file, the insurer investigates — confirming its policyholder’s coverage, reviewing the police report, sometimes inspecting your vehicle. Until it accepts liability, it generally owes you nothing: no rental car, no loss-of-use payment, no repairs. For many victims this gap lasts weeks, and they sit without a car wondering why “the other guy’s insurance” will not help.

Bridge the gap proactively:

Use your own collision coverage to get your car repaired immediately, then let your insurer recover the cost (including your deductible) from the at-fault insurer through subrogation. This is usually the fastest route back on the road.
Check for rental-reimbursement coverage on your own policy — it pays for a rental while your car is being repaired, regardless of fault.
Track your loss of use. Loss of use is generally calculated as the daily rental value of a comparable vehicle multiplied by the reasonable number of repair days — and some jurisdictions allow you to recover it even if you never rented a car. Keep a log of every day you were without your vehicle; it becomes a line item in your demand.

If liability is clear (for example, a rear-end collision with a police report citing the other driver), push the adjuster for an early liability decision in writing. Once liability is accepted, rental and repair authorisation typically follow within days.

Step 6: Document Your Damages Continuously

Filing the claim is the beginning, not the end, of documentation. From the crash date until settlement, maintain a running damages file:

Medical: every bill, every appointment, every prescription — plus a simple pain journal noting pain levels, missed activities, and how injuries affect daily life. Insurers discount what they cannot see; a contemporaneous journal makes suffering concrete.
Property: repair estimates (get two independent ones), photos of damage, receipts for towing and storage.
Income: updated employer letters and pay stubs for every missed pay period.
Out-of-pocket: keep every receipt in one envelope or scanned folder — mileage to medical appointments is claimable too (track dates and distances).

Do not post about the accident, your injuries, or your activities on social media. Insurers routinely monitor claimants’ public profiles, and a single photo of you carrying groceries can be used to argue your back injury is exaggerated.

Step 7: Evaluate the Settlement Offer Like an Adjuster Does

When the insurer makes an offer, your job is to reverse-engineer it. A fair settlement accounts for every category of loss — not just the repair bill. Break any offer into these components and check each one:

Medical specials: the total of all past medical bills, plus a reasonable estimate of future treatment your doctor says you will need. Insurers typically anchor on the bills; your leverage is the future care they would rather not think about.
Lost wages and earning capacity: documented income lost to date, plus any reduced future earning capacity if the injury is permanent or long-lasting. Self-employed claimants should present tax returns and a clear before/after income comparison.
Pain and suffering: the non-economic component — physical pain, emotional distress, loss of enjoyment of life. Adjusters often start from a multiple of medical specials (commonly 1.5× to 5× depending on injury severity), though the multiplier is a negotiating shorthand, not a law. Serious, well-documented injuries with continuous treatment command the higher end.
Property damage and loss of use: repair or fair-market value (if totalled), towing, storage, and the daily rental value for every day you were without the vehicle.
Out-of-pocket costs: every receipt in your file — mileage, medications, equipment, help at home.

Add these up. If the offer covers only medical bills and repairs while ignoring wage loss and pain and suffering, it is a lowball — which first offers almost always are. Do not accept the first number, and never settle before your medical treatment is complete; once you sign a release, you cannot reopen the claim even if complications appear later.

Step 8: Negotiate From a Position of Paper

Negotiation with a third-party adjuster is a slow exchange of documented positions, not a single dramatic phone call. The standard tool is the demand letter: a formal written package stating your version of the facts, itemising every category of damages with supporting documents, and naming a settlement figure. A strong demand letter routinely moves the insurer far more than any phone argument. Our guide explains exactly what a demand letter is and how to structure one for maximum effect.

When you negotiate, follow the tactics that experienced claimants use: anchor your demand above your true target (leaving room to concede), respond to each insurer counter in writing with specific rebuttals tied to documents, and never reveal your bottom line or any personal financial pressure. Adjusters are trained negotiators who negotiate claims all day — but they also have authority limits and caseloads, and a well-documented file is expensive for them to fight. For the full playbook, see how to negotiate with an insurance adjuster after a car accident.

Deadlines and State Differences You Cannot Ignore

Two state-level variations change the entire shape of your claim:

Fault vs no-fault (PIP) states

About a dozen states use no-fault systems (including Florida, New York, Michigan, New Jersey, and Pennsylvania in various forms). In these states, your own PIP coverage pays your initial medical bills and lost wages regardless of fault — so your first claim after a crash is usually against your own policy, not the at-fault driver’s.

You can still file a third-party claim against the at-fault driver’s insurer, but only if your injuries cross the state’s tort threshold (a statutory seriousness standard, such as significant disfigurement, fracture, or a minimum medical-expense figure). In fault-based states, by contrast, the third-party claim is your primary route from day one, and you must prove the other driver’s fault to collect. Know your state’s system before you file — filing the wrong type of claim first wastes weeks.

Statute of limitations varies widely

The lawsuit-filing deadline ranges roughly from one year (Kentucky, Louisiana, Tennessee) to two or three years in most states, with some allowing up to six. The clock usually starts on the crash date. Because a filed lawsuit is your ultimate leverage in settlement talks, calendar this deadline the day you file your claim — and if the deadline is approaching with no settlement, consult an attorney well before it expires, since preparing a lawsuit takes time.

Step 9: If They Deny Your Claim — The Escalation Path

A denial letter feels final. It is not. It is the insurer’s negotiating position, not a legal verdict, and many denied claims are paid after proper escalation. Work this ladder in order:

Demand the denial in writing with specific reasons. Vague denials (“we are unable to accept liability”) are not enough. You are entitled to know exactly which policy provision, exclusion, or factual finding the insurer relies on — that specificity is what you attack.
Supplement the evidence. Most denials rest on claimed gaps: disputed fault, alleged pre-existing conditions, or treatment the insurer calls “excessive.” Counter each point with documents — the police report’s fault findings, witness statements, your doctor’s letter distinguishing the crash injury from any prior condition, treatment guidelines supporting the care you received. Resubmit formally and request reconsideration.
File a complaint with your state’s insurance department. Every state has a regulator (find yours through USA.gov’s state insurance directory) that accepts consumer complaints against insurers. Regulators cannot decide fault, but a complaint triggers a formal response requirement and an internal review at the insurer — adjusters take these seriously. The Insurance Information Institute (iii.org) also publishes clear guidance on how the claims process should work, which helps you spot when an insurer deviates from standard practice.
Watch for bad faith. Unreasonable delays, misrepresenting policy terms, or refusing to investigate can cross the line into bad faith — which may entitle you to penalties beyond your original damages. Learn the warning signs in our guide to bad-faith insurance claims and how to fight back.
Sue. Small-claims court handles property-damage and smaller injury claims quickly and cheaply (limits typically $5,000–$10,000 depending on the state, no lawyer required). Larger injury claims belong in civil court, where an attorney working on contingency (no upfront fee — they take a percentage of the recovery) makes representation accessible. Filing suit before the statute of limitations expires preserves every option.

Key Takeaway: How to File a Claim With the At-Fault Driver’s Insurance Company

Learning how to file a claim with the at-fault driver’s insurance company gives you real leverage: a third-party claim means you are asking their insurer to pay you — an insurer that owes you no loyalty and will protect its own money. Your power comes from three things: airtight documentation of fault and damages, prompt action that respects notice rules and the statute of limitations, and disciplined communication that gives the adjuster facts without handing them ammunition. Bridge the investigation gap with your own coverage, negotiate from a written demand backed by evidence, and remember that a denial letter is a negotiating position, not a verdict — supplement your evidence, complain to your state insurance department, or sue before your deadline expires.

Disclaimer: This article provides general information for educational purposes only and is not legal advice. Insurance rules, claim deadlines, and available remedies vary from state to state and depend on the specific terms of the policies involved. For guidance about your situation, consult a licensed attorney in your state.

Frequently Asked Questions

What if the at-fault driver won’t give me their insurance information?

File the claim anyway using the police report, the licence-plate number, and the vehicle description — insurers can usually identify their policyholder from these details. At the same time, notify your own insurer and use your collision and uninsured-motorist coverage so repairs and treatment are not delayed. Your insurer can pursue the at-fault party afterwards through subrogation.

Can I file a claim if I was partially at fault?

In most states, yes. The majority follow comparative-fault rules, meaning your compensation is reduced by your percentage of fault — if you were 20% at fault for a $50,000 claim, you recover $40,000. A minority of states use harsh contributory-negligence rules that can bar recovery entirely if you share any fault. Do not assume partial fault disqualifies you; the insurer still has to prove your share of blame.

How long does it take to get paid on a third-party claim?

Property-damage-only claims often resolve in 30–60 days once liability is accepted. Injury claims typically take several months because you should not settle until treatment is complete and the full cost is known. Complex or disputed claims can take a year or more. State regulations require insurers to acknowledge and decide claims within set timeframes, so an adjuster who goes silent is violating rules you can cite.

Should I give the at-fault insurer a recorded statement?

No — not on the first call, and ideally never without preparation. You have no legal obligation to give a recorded statement to the other driver’s insurer, and these statements are designed to capture inconsistencies the insurer can use against you later. Provide a written account with your documentation instead, and decline politely but firmly.

What if the at-fault driver’s policy limits are too low to cover my damages?

This happens constantly — minimum-liability states allow limits as low as $25,000 per person, which a single emergency-room visit can exceed. Your options are your own underinsured-motorist coverage, a personal claim against the at-fault driver’s assets, and stacking any applicable MedPay or umbrella coverage. Review how underinsured-motorist claims work before you accept a limits-only settlement.

Do I need a lawyer to file a third-party claim?

Not for straightforward property-damage claims with clear liability. But if you suffered significant injuries, liability is disputed, the insurer is stalling or denying, or the statute of limitations is approaching, an attorney substantially changes the outcome — most personal-injury lawyers work on contingency, so there is no upfront cost. At minimum, get a free consultation before signing any release.

Can I choose my own repair shop?

Yes. You have the right to have your vehicle repaired at the shop of your choice; the insurer cannot force you to use its “preferred” network, though it only has to pay reasonable and customary repair costs. Get two independent written estimates to establish what is reasonable, and keep the insurer’s lowball estimate from becoming the ceiling.

What is “loss of use” and can I claim it if I never rented a car?

Loss of use compensates you for being deprived of your vehicle during repairs — generally the daily rental value of a comparable car multiplied by the reasonable number of repair days. Many jurisdictions allow recovery even if you never actually rented a replacement, since the loss is the use of the car, not the rental receipt. Log every day you were without your vehicle.

The adjuster offered me money within days of the crash. Should I take it?

Almost certainly not. Early offers are calibrated to close your file before the full extent of your injuries and expenses is known — soft-tissue injuries and complications routinely surface weeks later. Once you sign a release, the claim is over permanently. Complete your treatment, document everything, and negotiate from a full picture of your damages.

What if the at-fault driver was uninsured?

Then there is no third-party insurer to file against, and your own uninsured-motorist coverage becomes your primary remedy — it is specifically designed for this scenario. File the claim with your insurer promptly, document exactly as you would a third-party claim, and consider a personal lawsuit against the driver if your damages exceed your coverage. This is also the moment to confirm you actually carry uninsured-motorist coverage before you need it again.