Area code
720
720 is a United States area code. Under the North American Numbering Plan it belongs to Colorado, which has 6 area codes in total.
Validate a number in 720
Paste a full number and the tool checks it against the numbering plan. It returns the standard formats, the line type the plan assigns and the area code region.
Digits with or without punctuation work. Numbers outside the US are read with the +country code.
Area code 720 at a glance
NANPA lists 785 central office codes (prefixes) in use in area code 720, held by 45 holders across 12 rate centers.
| Fact | Value |
|---|---|
| In service since | 1998-06-01 |
| Time zone | Mountain (M) |
| Assigned overlays | 303 (1947-01-01), 983 (2022-06-17) |
| Prefixes in use | 785 |
| Pooled prefixes | 653 (83%) |
| Rate centers | 12 |
| Companies holding prefixes | 45 |
| Assignment dates on file | 2001-01-12 to 2024-09-03 (508 prefixes) |
| ZIP codes in its places | 78 |
Rate centers in area code 720
The largest rate center is DENVER, with 678 prefixes (86%).
| Rate center | Prefixes | Share |
|---|---|---|
| DENVER | 678 | 86% |
| LONGMONT | 39 | 5% |
| FORTLUPTON | 14 | 2% |
| GEORGETOWN | 11 | 1% |
| ALLNSPKLYN | 10 | 1% |
| DECKERS | 10 | 1% |
| KEENESBURG | 9 | 1% |
| HUDSON | 8 | 1% |
| 4 other rate centers | 6 | <1% |
Who holds the prefixes in 720
T-Mobile USA holds the most prefixes, 132 (17%). 83% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
| Holder | Prefixes | Share |
|---|---|---|
| T-Mobile USA | 132 | 17% |
| Qwest | 103 | 13% |
| New Cingular Wireless PCS | 92 | 12% |
| Verizon Wireless | 75 | 10% |
| Bandwidth.com CLEC | 55 | 7% |
| Onvoy | 55 | 7% |
| 39 other carriers | 273 | 35% |
A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. Find which carrier a number is on, or browse the prefix holders.
History of area code 720
- 1947-01-01 Area code 303, named as the parent of 720 in the NANPA report, was in service.
- 1998-06-01 Area code 720 went into service.
Area codes nearest to 720
Distance is measured between the centers of the ZIP code places each area code serves, so it is a rough guide.
Overlay codes in the same area
ZIP codes in area code 720
78 ZIP codes fall in places that have a rate center in this area code.
| Place | ZIP codes |
|---|---|
| Denver, CO | 66 |
| Longmont, CO | 4 |
| Bennett, CO | 1 |
A ZIP code and an area code are unrelated systems. A ZIP code can sit in more than one area code, and an area code spans many ZIP codes.
Complaints on file for 720 numbers
6,366 FCC complaints are on file for 4,593 numbers in 720, most often filed as "Unwanted Calls". These are unverified consumer reports.
| Year of latest complaint | Numbers |
|---|---|
| 2023 | 232 |
| 2024 | 230 |
| 2025 | 265 |
Other area codes in Colorado
Colorado is one state with 6 area codes in the NANPA table. 720 is one of them.
Next to 720 in the numbering table
These are the codes just before and after 720 when all are sorted by number. They are neighbours on the list, not necessarily on the map.
What the area code does and does not tell you
A number that starts with 720 was first assigned in Colorado. That is a fact about where the number began, and it is a useful hint when you check a form entry, for example a billing address in Colorado next to a 720 phone number.
It does not show where the person is today. A number stays with its owner after a move or a change of provider (number portability), and mobile numbers travel with the handset. The area code also cannot tell you whether the line is active, who the carrier is, or whether the number is mobile or fixed: the plan shares those ranges. Read more about the area code, the numbering plan and line type.
Check numbers in bulk with the API
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
| Phone Intelligence (carrier and line status) | 1 credit per check (invalid numbers outside the US and Canada are free) | Product page |
Questions about area code 720
Where is area code 720?
NANPA assigns area code 720 to Colorado, United States.
In which state does area code 720 sit?
Colorado. 720 is one of 6 area codes the NANPA table assigns to the state.
Which places does area code 720 cover?
The places with the most ZIP codes among the rate centers in 720 are Denver, CO, Longmont, CO and Bennett, CO. The rate center list on this page shows all of them.
Who owns area code 720?
NANPA assigns area codes. Within 720, T-Mobile USA holds the most prefixes, 132 prefixes or 17%.
Which time zone does 720 use?
The NANPA NPA report lists the time zone for 720 as Mountain (M).
What year did 720 enter service?
The NANPA NPA report gives an in-service date of 1998-06-01, so 720 has been in use since 1998.
Does area code 720 have an overlay?
Yes. 303 (in service 1947-01-01) and 983 (in service 2022-06-17) share the same area with 720, so numbers from all of them are local to each other.
Which area codes are nearest to 720?
The area codes closest to 720, measured between the centers of the ZIP code places they serve, are 970 (about 61 miles), 719 (about 111 miles), 307 (about 235 miles), 308 (about 254 miles) and 505 (about 298 miles).
How many prefixes does area code 720 have?
NANPA's report dated 2026-10-17 lists 785 prefixes in service in 720, spread over 12 rate centers and 45 holders.
Are there complaints about 720 numbers?
The FCC data on file has 6,366 complaints for 4,593 numbers in 720. They are unverified consumer reports. A number with no complaints on file is not proven safe.
Area code assignments: North American Numbering Plan Administrator NPA report, file dated 10/17/2026, retrieved 2026-10-17. Source file. New codes are assigned several times a year. Prefixes, rate centers, holders, time zone, in-service date and overlays: NANPA central office code report dated 2026-10-17 and NPA report dated 2026-10-18. Complaints: FCC consumer complaints open data, fetched 2026-10-17. ZIP code places: Postal code places and coordinates: GeoNames (geonames.org), licensed CC BY 4.0.