301 area code
Where the 301 area code is, its overlay and how to dial a +1 301 number from anywhere.
The 301 area code is in Aspen Hill, Maryland, United States (Eastern (ET)). To call from abroad: +1 301 555-0123. It is an overlay, so all 10 digits are dialled.
The 301 area code is a geographic North American Numbering Plan (NANP) code covering Aspen Hill, Maryland. It has been in service since 01-Jan-1947 and sits in the Eastern (ET) time zone.
How to dial a 301 number
+1 301 555-01231 301 555-0123301 555-0123Cities in the 301 area code
A 301 number is usually in one of these places in Maryland — 6 counties.
Other Maryland area codes
Frequently asked questions
Where is the 301 area code?
The 301 area code is in Aspen Hill, Maryland, United States (Eastern (ET)).
Is 301 an overlay area code?
Yes. 301 overlays the same region as 227, 240, so callers dial all 10 digits.
Do I have to dial 10 digits for 301?
Yes — dial the area code plus the seven-digit number.
How do I call a 301 number from another country?
Dial your exit code (or +), then 1, then 301, then the number: +1 301 555-0123.
Source: NANPA numbering plan. An area code covers a region, not a precise address — a 301 number does not pinpoint a street or ZIP code.
Number holders in area code 301
Each prefix (the three digits after the area code) is assigned by NANPA to one telephone company. 800 prefixes are in use in 301, shared by 33 companies. The largest holders:
| Company | Prefixes | Share |
|---|---|---|
| Verizon Maryland, Inc. | 465 | 58% |
| Cellco Partnership Dba Verizon Wireless | 51 | 6% |
| New Cingular Wireless PCS, LLC | 47 | 6% |
| Mcimetro Access Transmission Services LLC | 40 | 5% |
| Omnipoint Communications Cap Operations, LLC | 31 | 4% |
| Teleport Communications America, LLC | 31 | 4% |
Source: NANPA central office code assignments. A number keeps its original prefix when it is ported to another carrier.
Complaints about 301 numbers
- Reports to the FTC, last 30 days
- 426
- Recorded messages or robocalls
- 54%
- Rank among area codes
- #233 of 670
- Most reported subjects
- Other (158)
- Calls pretending to be government, businesses, or family and friends (59)
- Reducing your debt (credit cards, mortgage, student loans) (48)
Period Aug 26 – Sep 24, 2026. These are the numbers shown on the caller ID of the reported calls; many are spoofed and do not belong to the real caller.
Source: US Federal Trade Commission, Do Not Call reported calls data (daily files).
All US area codes United States +1 Map of area code 301 — cities & rate centres