Prefix 414-243 — Milwaukee Zone 1, WI

NANPA CO code assignment, current as of July 28, 2026.

Area code
414
Prefix (NXX)
243
Rate center
Milwaukee Zone 1
State
Wisconsin
Time zone
Central
Code holder
T-MOBILE USA, INC.
OCN
6529
Pooled
Yes (thousands-block pooling)
Assigned
2003-01-22
LATA
356

Numbers in the 414-243 prefix are registered to the Milwaukee Zone 1 rate center in WI, inside area code 414. The prefix is the second block of a ten-digit US number (414-243-XXXX) and pins the number to a billing locality.

The assigned code holder is T-MOBILE USA, INC., operating company number 6529, assigned January 22, 2003. This is a pooled prefix — expect numbers within it to be split across more than one carrier in 1,000-number blocks.

The rate center lies in the Milwaukee-Waukesha, WI Metropolitan Statistical Area. The serving LATA is 356. Local time follows the Central zone.

Spoofing means this prefix on your screen doesn't guarantee a Milwaukee Zone 1 caller. Verify independently before trusting a request for money or data.

Neighboring prefixes

Prefixes adjacent to 414-243
PrefixRate centerCode holder
414-240 Milwaukee Zone 1 ONVOY, LLC - WI
414-241 Milwaukee Zone 5 T-MOBILE USA, INC.
414-242 Milwaukee Zone 1 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - WI
414-244 Milwaukee Zone 1 WISCONSIN BELL INC
414-245 Milwaukee Zone 1 WISCONSIN BELL INC
414-246 Milwaukee Zone 3 ONVOY, LLC - WI

FAQ

Where is 414-243 located?

The prefix is assigned to the Milwaukee Zone 1 rate center in WI, area code 414. It is part of the Milwaukee-Waukesha, WI Metropolitan Statistical Area.

Which company owns 414-243 numbers?

T-MOBILE USA, INC. holds the code, but the prefix is pooled — individual thousands-blocks can be assigned to other carriers, and numbers may be ported to any provider.

Is a call from 414-243 safe to answer?

The prefix itself says nothing about the caller. Legitimate Milwaukee Zone 1 businesses and spoofed robocalls can both display it. Never share personal data with an unverified inbound caller.