ZIP Codes in Saint Charles, MO
Saint Charles uses 3 ZIP codes, all in St. Charles County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 3 Saint Charles ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 63301 | standard | St. Charles | 52,667 |
| 63303 | standard | St. Charles | 46,089 |
| 63304 | standard | St. Charles | 43,195 |
Finding a ZIP+4 in Saint Charles
Knowing which of these 3 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same Saint Charles street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
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