ZIP Code 66603 — Topeka, KS
66603 is a standard (street delivery) ZIP code serving Topeka, Kansas, in Shawnee 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 66603 at a glance
| ZIP code | 66603 |
|---|---|
| Primary city | Topeka |
| State | Kansas (KS) |
| County | Shawnee FIPS 20177 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,830 |
| Coordinates | 39.057420, -95.675390 |
How ZIP+4 works in 66603
The four digits after the hyphen encode a delivery segment inside 66603. 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 66603 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 Topeka
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 66603.
| ZIP | City | Distance |
|---|---|---|
| 66612 | Topeka, KS | 1.2 mi |
| 66608 | Topeka, KS | 1.6 mi |
| 66621 | Topeka, KS | 2.2 mi |
| 66607 | Topeka, KS | 2.4 mi |
| 66606 | Topeka, KS | 2.6 mi |
| 66616 | Topeka, KS | 2.9 mi |
| 66604 | Topeka, KS | 3 mi |
| 66611 | Topeka, KS | 3.1 mi |
| 66622 | Topeka, KS | 3.3 mi |
| 66605 | Topeka, KS | 3.9 mi |
| 66609 | Topeka, KS | 5.2 mi |
| 66617 | Topeka, KS | 6.2 mi |
Questions about 66603
What is the ZIP+4 code for 66603?
66603 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 66603, you need to look up a specific street address to get them.
What city is 66603?
66603 is assigned to Topeka, Kansas, in Shawnee 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.