ZIP Code 77318 — Willis, TX
77318 is a standard (street delivery) ZIP code serving Willis, Texas, in Montgomery 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 77318 at a glance
| ZIP code | 77318 |
|---|---|
| Primary city | Willis |
| State | Texas (TX) |
| County | Montgomery FIPS 48339 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 20,792 |
| Coordinates | 30.447090, -95.543640 |
How ZIP+4 works in 77318
The four digits after the hyphen encode a delivery segment inside 77318. 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 77318 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.
Other ZIP codes in Willis
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 77318.
| ZIP | City | Distance |
|---|---|---|
| 77304 | Conroe, TX | 8.2 mi |
| 77358 | New Waverly, TX | 8.9 mi |
| 77356 | Montgomery, TX | 9.5 mi |
| 77378 | Willis, TX | 10.1 mi |
| 77303 | Conroe, TX | 10.9 mi |
| 77301 | Conroe, TX | 11.6 mi |
| 77316 | Montgomery, TX | 12.7 mi |
| 77340 | Huntsville, TX | 13.7 mi |
| 77384 | Conroe, TX | 14.9 mi |
| 77382 | Spring, TX | 17.1 mi |
| 77341 | Huntsville, TX | 17.3 mi |
| 77354 | Magnolia, TX | 17.5 mi |
Questions about 77318
What is the ZIP+4 code for 77318?
77318 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 77318, you need to look up a specific street address to get them.
What city is 77318?
77318 is assigned to Willis, Texas, in Montgomery 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.