Kentucky ZIP Codes: Ranges, Prefixes and Major Cities

ZIP codes  |  April 8, 2026  |  2 min read

Kentucky uses 944 active ZIP codes, running from 40003 to 42788. This guide shows how those codes are grouped, which ones serve the state's largest cities and how to format them correctly.

ZIP code range and prefixes

Every Kentucky ZIP code starts with one of 27 three-digit prefixes. Each prefix points to a sectional center facility, the processing plant that sorts mail for a group of nearby post offices.

• 400
• 401
• 402
• 403
• 404
• 405
• 406
• 407
• 408
• 409
• 410
• 411
• 412
• 413
• 414
• 415
• 416
• 417
• 418
• 420
• 421
• 422
• 423
• 424
• 425
• 426
• 427

Types of ZIP codes in Kentucky

ZIP codes for major Kentucky cities

Frankfort is the state capital. Larger cities have many ZIP codes because each code follows mail delivery routes, not city limits.

Sample addresses

These examples use real city and ZIP pairs with invented street lines, so they are safe for testing and documentation.

Tips for working with these ZIP codes

• Store ZIP codes as text, not numbers, so the format stays consistent across states with leading zeros.
• Kentucky spans more than one time zone (Eastern and Central). Use the ZIP code or county, not the state, to decide local time.
• A quick sanity check: a valid KY ZIP code begins with one of the prefixes listed above.
• City names in addresses are post office names. A suburb may share a ZIP code and city name with a nearby larger town.