ZIP Code 95558 — Petrolia, CA
95558 is a standard (street delivery) ZIP code serving Petrolia, California, in Humboldt County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 95558 at a glance
| ZIP code | 95558 |
|---|---|
| Primary city | Petrolia |
| State | California (CA) |
| County | Humboldt FIPS 06023 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 230 |
| Coordinates | 40.326730, -124.240170 |
How ZIP+4 works in 95558
The four digits after the hyphen encode a delivery segment inside 95558. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 95558 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 95558.
| ZIP | City | Distance |
|---|---|---|
| 95545 | Honeydew, CA | 9.3 mi |
| 95562 | Rio Dell, CA | 11.4 mi |
| 95536 | Ferndale, CA | 12.8 mi |
| 95565 | Scotia, CA | 15 mi |
| 95571 | Weott, CA | 15.9 mi |
| 95540 | Fortuna, CA | 17.6 mi |
| 95547 | Hydesville, CA | 18.8 mi |
| 95569 | Redcrest, CA | 20.2 mi |
| 95528 | Carlotta, CA | 20.2 mi |
| 95553 | Miranda, CA | 20.5 mi |
| 95589 | Whitethorn, CA | 21.7 mi |
| 95551 | Loleta, CA | 23.7 mi |
Questions about 95558
What is the ZIP+4 code for 95558?
95558 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 95558, you need to look up a specific street address to get them.
What city is 95558?
95558 is assigned to Petrolia, California, in Humboldt County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.