A desk clock beside stacked forms representing the accident report deadlines after a Rancho Cucamonga crash
Quick answer: Three clocks: Police — immediately for injury crashes (and hit-and-runs — this one gates UM claims). DMV — the SR-1 report is due within 10 days whenever anyone is injured or damage exceeds $1,000, regardless of fault. Your insurer — “prompt notice” per your policy, best read as days, not weeks. Late reporting rarely kills a claim by itself — but it hands the insurer arguments for free.

Clock 1: The police report

Injury crashes should get law enforcement at the scene — the California Highway Patrol on the freeways, Rancho Cucamonga PD on surface streets. No response? You can file a counter report afterward; sooner preserves credibility. For hit-and-runs, this clock is unforgiving: UM policies typically require a prompt police report as a condition of coverage — report the same day.

Clock 2: The DMV's SR-1 — the one everyone misses

California requires an SR-1 report to the DMV within 10 days of any crash with injury (however slight), death, or property damage over $1,000 — which, at today's repair costs, is nearly every crash. It applies regardless of fault and separate from any police report. Missing it risks license suspension; it takes ten minutes online. File it early in week one and forget about it.

Clock 3: Your insurance policy

Policies require “prompt” notice — deliberately vague, practically meaning: call within days. Late notice invites a prejudice argument (“we couldn't investigate”) that can complicate even a strong claim, and specific coverages (UM, med-pay) often carry their own tighter conditions. Notifying YOUR insurer is not an admission of anything; it's a policy condition.

Reporting late: triage, not despair

Missed a window? File what's still fileable today — a late counter report and SR-1 beat none, and late insurer notice with an explanation beats silence. Then get the whole picture reviewed: late reporting is a complication attorneys handle constantly, and it matters far less in a well-documented claim. What the reports feed into is the bigger 30-day picture in the first-24-hours guide — and if the crash involved injuries, a fled driver, or a coverage fight, get a free case review now rather than after the next deadline.