983 Area Code: Denver, Colorado
Area code 983 serves Denver, Longmont and Fort Lupton, Colorado in the Mountain time zone, in service since 2022. Consumers have filed 532 unwanted-call complaints against 457 different 983 numbers, 133 of them with the FTC in the last 30 days. Look up the exact number that called you below.
Area code 983 at a glance
- State
- Colorado
- Main cities
- Denver, Longmont, Fort Lupton, Strasburg, Deckers, Roggen
- Counties
- Denver County, Boulder County, Weld County, Arapahoe County + 1 more
- Local time
- —Mountain
- In service since
- June 17, 2022
- Overlay of
- 303
- Overlay code
- 720 (1998)
- Local dialing
- 10 digits (area code + number)
- Exchanges
- 6 rate centers, 48 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 983 numbers
No single 983 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 983 numbers are about
410 FTC Do Not Call complaints about 983 numbers since Jul 24. The most common named subject is debt-relief pitches, at 38% of complaints (93% of those were recorded messages). Overall, 74% of callers who answered said the call was a robocall.
FTC complaint subjects
- Debt reduction15638%
- Other / unspecified15237%
- Dropped call / no message297%
- No subject given246%
- Home improvement & cleaning184%
- Impostor (government, business, family)133%
- Vacation & timeshares51%
FCC complaints by call type, last 2 years
- Prerecorded Voice3258%
- Live Voice1935%
- Text Message47%
Live-voice calls are from a person; prerecorded calls are robocalls.
When 983 spam calls come in
33% of complaints that give a call time describe calls between 11am and 2pm. 90% came Monday to Friday, most on Mondays, 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?
132 FTC complaints about 983 numbers in the last four weeks, down 12% on the four weeks before. FCC complaints about 983 numbers peaked in 2016 (34); 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 23% of the FTC complaints about 983 numbers came from Colorado residents; the most came from Florida, Texas and New York. 983 numbers are being used for nationwide campaigns, so the area code says little about where the caller is.
Where complainants live
- Colorado9323%
- Florida359%
- Texas297%
- New York277%
- California236%
Likely campaigns using 983 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 983 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.
| Prefix | Complaints | Numbers | Carrier | Exchange |
|---|---|---|---|---|
| (983) 226-xxxxcampaign | 49 | 48 | Onvoy (Sinch) | Longmont |
| (983) 221-xxxx | 41 | 34 | Onvoy (Sinch) | Deckers |
| (983) 212-xxxx | 5 | 4 | Onvoy (Sinch) | Denver |
Carriers operating in 983
NANPA has assigned 48 983 prefixes (NPA-NXX central-office codes) across 7 rate centers: 17% to wireless carriers, 67% to landline and VoIP operators; 94% are pooled blocks shared by several carriers. 18 prefixes were assigned in the last 12 months (newest 2026-10-20). 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 |
|---|---|---|---|---|
| Onvoy (Sinch) | Competitive / VoIP (CLEC) | 13(27%) | 4 | 2026-10-20 |
| Wide Voice, LLC | Competitive / VoIP (CLEC) | 7(15%) | 2 | 2026-06-16 |
| AT&T Mobility (New Cingular Wireless PCS) | Wireless | 4(8%) | 2 | 2026-05-06 |
| Verizon Wireless (Cellco Partnership) | Wireless | 3(6%) | 1 | 2026-09-29 |
| Shelcomm | Unclassified | 3(6%) | 3 | 2024-09-05 |
| Ahoi LLC | Unclassified | 2(4%) | 2 | 2025-11-18 |
| Onvoy (Sinch) | Competitive / VoIP (CLEC) | 2(4%) | 2 | 2025-01-27 |
| Opentact INC. | Unclassified | 2(4%) | 1 | 2026-03-19 |
| Teleport Communications America, LLC | Competitive / VoIP (CLEC) | 2(4%) | 1 | 2025-10-08 |
| 8x8, INC. | Competitive / VoIP (CLEC) | 1(2%) | 1 | 2026-09-11 |
| Allo Communications LLC | Competitive / VoIP (CLEC) | 1(2%) | 1 | 2025-09-02 |
| Bandwidth.com | Competitive / VoIP (CLEC) | 1(2%) | 1 | 2024-09-20 |
Largest rate centers (exchanges) by prefixes: Denver (33), Longmont (7), Fort Lupton (3), Strasburg (2), Deckers (1), Keenesburg (1), Roggen (1). Source: NANPA Central Office Code Utilized Assignments (public, refreshed weekly).
What to do about calls from 983 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 983 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 Colorado
- 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: Colorado Attorney General.
- Colorado is one of the states that maintains its own Do Not Call registry alongside the federal National Do Not Call Registry, so telemarketers calling Colorado 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 983: questions answered from the data
Where is area code 983?
Area code 983 serves Denver, Longmont and Fort Lupton, Colorado, covering Denver County, Boulder County and Weld County and 2 more counties. It has been in service since June 17, 2022.
What time zone is area code 983 in?
Area code 983 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.
Which area codes overlay 983?
720 (in service 1998) serves the same area as 983. New numbers there can be issued with any of these codes, and local calls need all 10 digits. A spoofed call can display any of them.
What are calls from 983 numbers usually about?
Since Jul 24, consumers filed 410 FTC Do Not Call complaints about 983 numbers. The most common named subject was debt-relief pitches: 38% of complaints, 93% of them recorded messages. Across all subjects, 74% of callers who answered the question said the call was a robocall.
When do 983 spam calls happen?
33% of the complaints that give a call time describe calls between 11am and 2pm, and 90% came on weekdays, most often on Monday. Times are as consumers reported them.
Are calls from 983 numbers really local?
Not necessarily. Only 23% of the FTC complaints about 983 numbers came from Colorado residents; the most came from Florida, Texas and New York. 983 numbers are being used for nationwide campaigns, so the area code says little about where the caller is.
Are 983 robocalls increasing?
In the four weeks to Oct 20, consumers filed 132 FTC complaints about 983 numbers, 12% fewer than the four weeks before.
How do I report a 983 scam call in Colorado?
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 Colorado, the Colorado Attorney General also handles consumer complaints about scam calls. Reports feed the public data this page is built from.
Overlay and nearby 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.