641 area code
Mason City area, Central Time.Area code 641 covers Mason City, New Haven, Marshalltown and 220 more places in Iowa, on Central Time.
Right now in Mason City
Central Time (CST, UTC-6; CDT, UTC-5 in summer)
Calling hours: Every day, 8 AM to 9 PM (the federal rule)
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Where 641 numbers come from
Numbers are issued by rate center, a billing area named for its main town. 641 has 223. Each one's share is how many 641 numbers start there. Its biggest metro area is Des Moines-West Des Moines, IA.
- Mason City3%
- New Haven3%
- Marshalltown3%
- Ottumwa3%
- New Hampton2%
- Oskaloosa2%
- Pella2%
Also: Charles City, Newton, Fairfield, Grinnell, Iowa Falls, Knoxville, Little Cedar, Osceola, Centerville, Clear Lake, Creston, Chariton + 204 more
Share of exchanges (blocks of 10,000 numbers). Source: NANPA rate center and exchange reports, November 10, 2026
When can you call a 641 number?
Sales calls to homes and cell phones have legal hours, set by the federal rule. Hold every 641 number to them, since you can't tell a work line from a personal cell.
What applies to 641Every day, 8 AM to 9 PM
- Federal (TCPA and FTC rule)Every day, 8 AM to 9 PMCalls to residential and mobile numbers. Most calls to businesses are exempt from the FTC's rule.47 CFR 64.1200(c)(1); 16 CFR 310.4(c) (opens in a new tab)
Local time comes from the area code, not from where the person is today. Mobiles keep their number when they move. Calling hours here are a guide, not legal advice. Every state's calling hours, with sources
The 641 area code
641 went into service on July 9, 2000, split off from 515. Local calls can still be dialed with 7 digits.
- 2000641 starts
Source: NANPA area code database
Other Iowa area codes
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641 area code FAQ
What area code is 641?
641 is an Iowa area code for Mason City, New Haven, Marshalltown, Ottumwa and 219 more places.
What time zone is the 641 area code in?
Central Time (CST, UTC-6; CDT, UTC-5 in summer).
What are the calling hours for 641 numbers?
Every day, 8 AM to 9 PM, local time, under the federal rule.
When did the 641 area code start?
On July 9, 2000. It was split from 515.
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