Data study · filed with regulators
Why Your ZIP Code Can Double Your Car-Insurance Rate
Updated
Two identical drivers, same car, same record — one across town from the other — can pay wildly different rates. The filings show exactly how much. In Nationwide's Pennsylvania filing, the priciest territory pays 7.6× the cheapest for bodily-injury coverage; at Mercury in Texas it's 4.4×. Every figure below is the carrier's own filed territory factor, transcribed from its SERFF filing.
Priciest vs. cheapest territory — the filed multiple
Each bar is that carrier's own priciest-territory bodily-injury factor divided by its cheapest — how many times more the most expensive area pays.
Cheapest and priciest areas, by carrier (SERFF-cited)
| Carrier / State | Cheapest area | Priciest area | Spread | SERFF |
|---|---|---|---|---|
| Nationwide — PA | 690 (0.394×) | 610 (2.995×) | 7.6× | NWPP-134410938 |
| Mercury — TX | 79005 (0.40×) | 78852 (1.74×) | 4.4× | MERY-134769395 |
| GEICO — VA | 312 (0.614×) | 213 (1.594×) | 2.6× | GECC-134876961 |
| USAA — AZ | 220 (0.6164×) | 292 (1.4151×) | 2.3× | USAA-134755352 |
Territory codes are the carrier's own rating territories (or ZIP, for Mercury). All figures are bodily-injury factors within a single carrier-state filing.
What this means for your rate
- Geography can be the single biggest lever. A 7.6× territory swing dwarfs the effect of a ticket, an accident, or even credit at most carriers.
- Moving a few miles can change your bill. Territory is set by where the car is garaged — a different ZIP, even in the same metro, can land you in a very different factor.
- Carriers draw the map differently. Your ZIP might be "cheap" at one insurer and "expensive" at another — which is why comparing carriers on your exact address matters.
- It's not the whole rate. These are the territory factors alone; your premium also reflects your driver profile, vehicle, and coverage.
Cite this data
Free to cite and reference with attribution. Every figure is a public SERFF filing you can independently verify.
Suggested citation:
FastAutoQuote, “How Much Your ZIP Code Moves Your Car-Insurance Rate,” an analysis of filed SERFF territory factors. https://fastautoquote.org/why-your-zip-changes-car-insurance
Machine-readable data: /api/v1/territory-spread.json · Media & data inquiries: press@fastautoquote.org
Related studies: Credit · Tickets & accidents · Driver age · Rate changes.
