The first 24 hours after someone else hits you shape your insurance claim, your repair, and your diminished value recovery. Here's exactly what to document, who to call, and what not to sign.
When someone else causes a collision, the first 24 hours are where the claim gets won or lost. Evidence disappears. The other driver's story changes. Witnesses leave town. Your medical symptoms, if you have them, sharpen over the next day or two. The actions you take in the first day determine what your repair looks like, what your diminished value claim can document, and whether you end up in a clean settlement or a contested one.
Here's the sequence, in order, for the first 24 hours after a not-at-fault accident.
Hour 0 to 1: at the scene
After confirming you and your passengers aren't hurt (or calling 911 if you are), the first hour is documentation.
Photos, many of them. Wide shots showing both vehicles in their final positions before anyone moves them. Close-ups of damage from multiple angles, including the panels adjacent to the impact point. Photos of the other driver's license plate, driver's license, and insurance card (get their phone and your phone both out, exchange plate photos with them, don't trust verbal numbers).
Environmental conditions. The road surface (wet, dry, visibility), signage, traffic signals, any skid marks or debris. These are what disputes about fault turn on three months later.
Witness information. If anyone saw the collision, get their name and phone number. Witnesses disappear fast after the scene clears, and a named witness with a phone number is a witness; a "someone told us what they saw" is not.
Police report. Call the police even if damage seems minor. A police report is often required by insurers for claims above a certain dollar threshold, and it's far easier to get a report at the scene than to file one after the fact. If the police decline to respond (common for no-injury parking-lot incidents), document that refusal; it becomes part of your claim record.
Hour 1 to 6: medical and reporting
Medical check, even if you feel fine. Whiplash, concussion, and soft-tissue injuries often take hours or days to present symptoms. The visit to urgent care or your doctor creates a medical record connected to the date of the accident, which is what ties any later symptoms to the collision for insurance purposes. Without that record, symptoms that show up three days later look unconnected.
Open your own insurance claim. Call your insurer and report the accident. Give them the basics: date, time, location, other driver's info, police report number if you have it. Do not speculate on fault. Do not give a recorded statement yet. You have the right to schedule a recorded statement after you've had time to review the facts; exercise that right.
Document vehicle damage separately from the scene photos. Once the vehicle is at home or in a tow yard, take a second round of photos in better light. These are your baseline for any diminished value claim and for the shop's pre-repair documentation.
Hour 6 to 24: the other driver's insurance
File a third-party claim with the at-fault driver's insurance. This is the claim that pays for your repair, your rental car, your medical bills if applicable, and your diminished value. Most insurers will take the call as soon as you have the other driver's policy number.
When you call, expect the adjuster to ask for a recorded statement. Your script: "I'd like to review everything once I'm home before giving a recorded statement. Please open the claim today and I'll schedule the statement for later this week." They will comply.
Do not accept any settlement offer in the first 24 hours. The at-fault driver's insurer may call you within hours with a fast settlement offer for "just the vehicle damage." This is almost always lower than the correct amount, and accepting it can waive your right to medical claims, diminished value, or future-symptom coverage. Decline politely: "I'm not accepting anything until I've completed the repair and medical review."
Do not sign anything, especially medical releases. The at-fault driver's insurer may ask you to sign a blanket medical release. Don't. This gives them access to your entire medical history, which they can use to argue that pre-existing conditions explain any new symptoms. You can provide specific medical records related to the accident without a blanket release.
The documentation checklist
By end of day one, you should have:
Scene photos (minimum 20, covering both vehicles, damage close-ups, license plates, environmental conditions)
Other driver's: name, phone, license number, insurance carrier, policy number, vehicle make/model/plate
Police report number (if available)
Witness names and phone numbers
Medical visit documentation tied to accident date
Your own insurance claim number
At-fault driver's insurance claim number (third-party)
A file folder (physical or digital) with all of the above
Documentation you didn't create in the first 24 hours almost never exists later.
Who calls whom
The chain of calls, in order:
911 if injuries or significant damage. Local non-emergency police for everything else. Your own insurance to open your first-party claim. The at-fault driver's insurance to open the third-party claim. Your shop of choice to begin the repair process.
Do not call the at-fault driver's insurance first, before opening your own claim. Your own insurer is an ally in the process even if the repair gets paid by the other side. They help with uninsured motorist coverage if the other side turns out not to have insurance, they often negotiate with the other carrier on your behalf, and they document the timeline of events on your behalf.
Choosing your repair shop
One thing not to do in the first 24 hours: choose your shop based on which shop the at-fault driver's insurer suggests. California Insurance Code §758.5 guarantees your right to choose your own shop, and the insurer's "preferred" shop is chosen for their benefit, not yours.
Take a few hours. Research shops. Look for I-CAR Gold Class certification, a true lifetime warranty, and a willingness to coordinate the claim on your behalf. Once you've chosen, tell both insurers (yours and the at-fault driver's) which shop will handle the repair. They'll work with the shop from there.
The mistake that costs people the most
The most common expensive mistake in the first 24 hours is taking the at-fault driver's first settlement offer. The offer usually arrives fast, feels reasonable, and comes with a release form that closes out the claim. Signed, that release usually also ends your rights to medical claims, diminished value, and future repair-related issues.
Not accepting anything in the first 24 hours doesn't delay your repair. Your shop starts the work as soon as you authorize it. The repair moves forward on the documented damage; settlement happens at the end when the actual costs are known.
A patient claim usually pays twice what a fast-settled claim does. The at-fault driver's insurer is counting on you to accept the fast number before you know the full cost. Don't.
What Crash Lab does after you've documented
Once you've chosen us, we handle the coordination with both insurers from there: claim intake, supplement negotiation, parts sourcing, repair execution, and delivery. Your job was the first 24 hours. Our job is everything after.
If you haven't yet been in an accident, save this article, bookmark our Accident Checklist lead magnet for a printable version to keep in your glovebox. The decisions you make in the first day are much easier when you've already rehearsed them.
If you are reading this in the first 24 hours after an accident, call (949) 859-7990 and we will walk you through the rest in real time. If you have not yet been in an accident, save this article and download our Accident Checklist for a printable version to keep in your glovebox.
Frequently Asked
What if the other driver admits fault at the scene?
Get it in writing if you can (a text message from them to you saying so is ideal), but don't rely on it. People often change their story after talking to their insurance company. Document everything as if fault is disputed, even when the other driver says it isn't.
Do I need a lawyer for a not-at-fault claim?
For property damage only, usually no. For claims involving personal injury, especially if symptoms persist beyond the first week, a consultation with a personal injury attorney is worth considering. Most offer free consultations and take cases on contingency, so the cost is limited to percentage of settlement if there is one.
What if I didn't take scene photos?
Photograph the damage now in detail, request a copy of the police report (which often includes officer-taken photos), check whether any nearby businesses have surveillance footage of the intersection or parking lot, and submit your insurance claim with whatever documentation you do have. You're in a weaker position than you'd be with full scene documentation, but not a fatal one.