Area code 301 – Maryland
301 is one of the original area codes, in service across Maryland since 1947. All but a handful of its 786 number blocks are allocated (784 of 786), so it is effectively exhausted. Verizon holds 71.0% of those blocks, which is unusually concentrated for a US area code. It shares its geography with overlay codes 227, 240, so local calls take all ten digits. FTC complaints naming a 301 caller ID totalled 477 in the 33 days to 30 October 2026 (217th of 422 ranked codes).
- State
- Maryland
- In service since
- 1947
- Time zone
- Eastern
Who holds 301 number blocks
Share of the 784 assigned NXX blocks (99.7% of the 786 possible), across 31 carriers. This is share of number blocks, not of subscribers.
- Verizon71%
- AT&T10.3%
- T-Mobile5.7%
- Other CLEC / VoIP2.9%
- Lumen2.6%
- Comcast1.5%
- Bandwidth1.4%
- Spok1.1%
- Windstream1.1%
- UScellular0.6%
- Onvoy0.6%
- Charter0.5%
- American Messaging0.1%
- Vonage0.1%
- Telnyx0.1%
Spam complaints naming 301
FTC Do Not Call complaints where the caller ID was a 301 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.
Rate centers in 301
NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 64.
Timeline
- 1947 301 assigned in the original North American Numbering Plan.
More about 301
Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.
Frequently asked about 301
What state is area code 301?
Maryland. It covers the same area as 240/227/301.
Can I still get a 301 number?
Only from recycled stock. 784 of the 786 available blocks are already allocated, so new numbers in the area normally come from the overlay codes (240/227/301).
Is a call from 301 a scam?
Not by itself. 301 drew 477 FTC complaints in the 33 days to 30 October 2026, 217th of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.
Which carrier owns 301 numbers?
Verizon holds the largest share of assigned number blocks at 71.0%. The rest is spread across 3 other carriers. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.
Do I need to dial 10 digits in 301?
Yes – ten digits for local calls in 301, because it shares its area with another code.
Sources and verification
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, retrieved Nov 1, 2026
- FTC – Do Not Call Reported Calls Data, 25 daily files 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.