Area code 641

Area code 641 at a glance

641 is one of 5 geographic area codes serving Iowa; NANPA records its in-service date as July 9, 2000. It is not part of an overlay, so every number in its territory starts with 641. It is in the Central time zone. The places with the most assigned exchanges include Mason City, Marshalltown, Ottumwa, Pella, and Oskaloosa. By population, its largest named places are Marshalltown, Mason City, Ottumwa, Newton, and Oskaloosa.

Places served by 641

641 holds 21% of the 2,748 central office codes assigned in Iowa, the 2nd most of the state's 5 codes. 199 Census places could be matched to rate centers with 641 exchanges; the most populous are Marshalltown (27,886), Mason City (26,948), Ottumwa (25,648), and Newton (15,709). Each place page lists the exact prefixes and carriers for that town.

How calls are dialed in 641

According to NANPA's dialing-plan data, local calls within 641 are dialed as seven digits and toll calls as 1 plus ten digits. Seven-digit local dialing is still permitted here, but customers calling from other area codes, and every mobile contact list, use all ten digits.

Carriers with 641 numbers

73 carriers hold the 584 central office codes assigned in 641. Windstream Iowa Communications, INC. has the most, with 60 (10%). 418 of the codes (72%) are pooled, meaning the code holder shares blocks of 1,000 numbers with other carriers instead of using all 10,000 itself. The code holder is not necessarily the carrier serving a given number today, since numbers can be ported between providers.

Rate centers and towns in 641

NANPA assigns each central office code to a rate center, the local calling area that decides whether a call is local or toll. 641 has codes in 223 rate centers. Rate center names in the file are abbreviations; where one matches a Census place, the table links to that city's local-number page.

641 code assignments over time

An area code has 800 possible central office codes that start with 2 through 9, a few of which are reserved (such as N11 service codes and 555). 584 are assigned in 641, 73% of 800. 106 were assigned in 2020 or later.

Using area code 641 for business calls

For $99 a month, Callata puts a team of up to 5 on one plan ($20 for each person after that): up to 3 local numbers, unlimited inbound calls, a pooled allowance of 1,500 outbound US and Canada minutes per user, browser and cell calling, voicemail transcription with urgency triage, recorded calls with AI summaries and business-hours routing, with E911 on every number.

Porting a number you already use in area code 641 is free, and business texting is available once the carrier registration (10DLC) is approved; the registration carries a one-time $49 fee. Which specific numbers are open in a given area code depends on carrier inventory at the time you sign up.

AI agents are optional: an AI receptionist or scheduler can pick up when the team is busy or closed, take a message, send a text or email, or transfer the call. They draw on prepaid AI minutes ($0.25/minute), disclose that they are AI, and outbound AI calls require prior consent and are limited to 8am–9pm.