307 Area Code: Cheyenne, Wyoming
Area code 307 serves Cheyenne, Casper and Gillette, Wyoming in the Mountain time zone, in service since 1947. Consumers have filed 3,939 unwanted-call complaints against 2,957 different 307 numbers, 282 of them with the FTC in the last 30 days. Look up the exact number that called you below.
Area code 307 at a glance
- State
- Wyoming
- Main cities
- Cheyenne, Casper, Gillette, Jackson, Laramie, Sheridan + 79 more
- Counties
- Laramie County, Natrona County, Fremont County, Teton County + 19 more
- Local time
- —Mountain
- In service since
- 1947
- Local dialing
- 7 digits allowed
- Exchanges
- 92 rate centers, 499 prefixes
Sources: NANPA area code and central office code records (refreshed weekly); cities and counties matched from US Census Bureau and USGS place names.
Reported 307 numbers
No single 307 number has enough complaints yet for a full report page, so none are listed. Look up the exact number that called you: the lookup works on every US number, whether or not it has complaint history.
What calls from 307 numbers are about
975 FTC Do Not Call complaints about 307 numbers since Jul 24. The most common named subject is debt-relief pitches, at 31% of complaints (91% of those were recorded messages). Overall, 71% of callers who answered said the call was a robocall.
FTC complaint subjects
- Other / unspecified40241%
- Debt reduction30531%
- No subject given11111%
- Impostor (government, business, family)546%
- Dropped call / no message404%
- Medical & prescriptions202%
- Home improvement & cleaning101%
FCC complaints by call type, last 2 years
- Live Voice8248%
- Prerecorded Voice6337%
- Text Message2716%
16% of recent FCC complaints about 307 numbers are about text messages, not calls.
When 307 spam calls come in
29% of complaints that give a call time describe calls between 12pm and 3pm. 90% came Monday to Friday, most on Thursdays, the pattern of call-center robocall campaigns that run on business hours. Times are as consumers reported them to the FTC.
By hour of the day
By day of the week
Is it getting worse?
307 FTC complaints about 307 numbers in the last four weeks, down 15% on the four weeks before. FCC complaints about 307 numbers peaked in 2015 (640); the FTC's daily Do Not Call data has carried most of the volume since mid-2026.
FTC complaints per week
FCC complaints per year
Years shown as '15 to '26; the current year is partial.
Who gets these calls
Only 32% of the FTC complaints about 307 numbers came from Wyoming residents; the most came from Texas, Florida and California. 307 numbers are being used for nationwide campaigns, so the area code says little about where the caller is.
Where complainants live
- Wyoming31332%
- Texas727%
- Florida697%
- California535%
- New York475%
What people with 307 numbers report
People whose own number starts with 307 filed 677 FTC complaints since Jul 24. 47% were about calls showing another 307 number. The most common named subject was debt-relief pitches.
Area codes on the calls they reported
- 307 (same code)32047%
- 866 (toll-free)284%
- 888 (toll-free)183%
- 833 (toll-free)162%
- 877 (toll-free)152%
Likely campaigns using 307 numbers
Groups of numbers that drew the same FTC complaint in the same pattern over the last 60 days. The grouping is statistical and doesn't identify who is calling.
Busiest 307 prefixes this month
FTC complaints in the last 30 days, grouped by the first six digits. When one prefix collects complaints about many different numbers, a campaign is usually cycling through that block. The carrier is who NANPA assigned the prefix to, not who made the calls.
Carriers operating in 307
NANPA has assigned 499 307 prefixes (NPA-NXX central-office codes) across 92 rate centers: 25% to wireless carriers, 71% to landline and VoIP operators; 56% are pooled blocks shared by several carriers. 8 prefixes were assigned in the last 12 months (newest 2026-09-11). The carrier holding a prefix is who the number was issued through. It says nothing about who is calling, since caller ID is routinely spoofed.
| Carrier | Type | Prefixes | Rate centers | Newest assignment |
|---|---|---|---|---|
| Qwest (CenturyLink / Lumen) | Incumbent landline (ILEC) | 83(17%) | 30 | 2008-03-10 |
| Union Telephone Company | Incumbent landline (ILEC) | 65(13%) | 44 | 2007-11-06 |
| Verizon Wireless (Cellco Partnership) | Wireless | 60(12%) | 25 | 2021-02-10 |
| AT&T Mobility (New Cingular Wireless PCS) | Wireless | 49(10%) | 38 | 2025-04-30 |
| Onvoy (Sinch) | Competitive / VoIP (CLEC) | 40(8%) | 24 | 2025-02-12 |
| Level 3 (Lumen) | Competitive / VoIP (CLEC) | 27(5%) | 20 | 2023-05-24 |
| Bandwidth.com | Competitive / VoIP (CLEC) | 19(4%) | 13 | 2022-07-19 |
| Rt Communications | Competitive / VoIP (CLEC) | 17(3%) | 15 | — |
| T-Mobile USA | Wireless | 14(3%) | 9 | 2025-12-03 |
| Union Tel. CO. | Incumbent landline (ILEC) | 11(2%) | 10 | — |
| Charter (Spectrum Voice) | Competitive / VoIP (CLEC) | 8(2%) | 5 | 2026-02-25 |
| Tri-County Tel. Assn., INC. | Unclassified | 7(1%) | 7 | — |
Largest rate centers (exchanges) by prefixes: Cheyenne (60), Casper (40), Gillette (21), Jackson (21), Laramie (18), Rock Springs (17), Sheridan (17), Cody (15), Evanston (13), Riverton (13). Source: NANPA Central Office Code Utilized Assignments (public, refreshed weekly).
What to do about calls from 307 numbers
Before you call back
- Debt reduction is the top named complaint here. Don't pay upfront fees for debt relief; the FTC's Telemarketing Sales Rule bans them. Talk to your lender or a nonprofit credit counselor instead. Read about debt-relief robocalls.
- Look up the full number above. A missed call from 307 with no voicemail is usually a robocall; anyone who needs you will leave a message.
- Block repeat callers: iPhone, Android, or your carrier's free filter (Verizon, AT&T, T-Mobile).
Report it in Wyoming
- Unwanted sales calls and robocalls: donotcall.gov (FTC). Scams and fraud: ReportFraud.ftc.gov.
- Spoofing, texts and call-blocking problems: FCC consumer complaints.
- State complaints: Wyoming Attorney General.
- Wyoming is one of the states that maintains its own Do Not Call registry alongside the federal National Do Not Call Registry, so telemarketers calling Wyoming numbers are expected to check both lists. Registering on the federal list at donotcall.gov is free and never expires; the state list is administered separately and may have its own registration process and renewal period.
Your FTC and FCC reports are published (without your name or number) in the datasets this page is built from. How to report unwanted calls.
Area code 307: questions answered from the data
Where is area code 307?
Area code 307 serves Cheyenne, Casper and Gillette, Wyoming, covering Laramie County, Natrona County and Fremont County and 20 more counties. It has been in service since 1947.
What time zone is area code 307 in?
Area code 307 is in the Mountain time zone (UTC−7, or UTC−6 during daylight saving time). The current local time is shown at the top of this page.
What are calls from 307 numbers usually about?
Since Jul 24, consumers filed 975 FTC Do Not Call complaints about 307 numbers. The most common named subject was debt-relief pitches: 31% of complaints, 91% of them recorded messages. Across all subjects, 71% of callers who answered the question said the call was a robocall.
When do 307 spam calls happen?
29% of the complaints that give a call time describe calls between 12pm and 3pm, and 90% came on weekdays, most often on Thursday. Times are as consumers reported them.
Are calls from 307 numbers really local?
Not necessarily. Only 32% of the FTC complaints about 307 numbers came from Wyoming residents; the most came from Texas, Florida and California. 307 numbers are being used for nationwide campaigns, so the area code says little about where the caller is.
Are 307 robocalls increasing?
In the four weeks to Oct 15, consumers filed 307 FTC complaints about 307 numbers, 15% fewer than the four weeks before.
How do I report a 307 scam call in Wyoming?
Report unwanted sales calls and robocalls to the FTC at donotcall.gov, and scams to ReportFraud.ftc.gov. The FCC takes complaints at consumercomplaints.fcc.gov. In Wyoming, the Wyoming Attorney General also handles consumer complaints about scam calls. Reports feed the public data this page is built from.
Other Wyoming area codes
Sources: FTC Do Not Call complaints (unverified consumer reports), published every weekday and available here from Jul 24; FCC Consumer Complaint Data, public record, imported nightly; NANPA numbering records. A number appearing here means consumers reported calls that displayed it. Caller ID can be spoofed.