🇺🇸 301 area code
Area code 301 covers Bethesda, Silver Spring, Gaithersburg and Rockville and the surrounding area in Maryland. It shares that territory with 240 and 227, so the same neighbourhood can have numbers in any of them. Enter a 301 number below for a free check before you call back.
- Location: Bethesda, Maryland
- Time zone: Eastern (UTC−5)
- In service since 1947
Look up a number
Validity, carrier, line type, and region on the first pass.
Area code 301 at a glance
- Area code
- 301
- Location
- Maryland, United States
- Main cities
- Bethesda, Silver Spring, Gaithersburg, Rockville, Frederick, Hagerstown
- Time zone
- Eastern (UTC−5)
- Local time now
- —
- In service since
- 1947
- Overlay codes
- 240, 227
- Codes split from it
- 227, 240, 410
- Local calls
- Dial 10 digits
- Number format
- (301) 555-0123
- From abroad
- +1 301 555 0123
Cities in area code 301
- Bethesda
- Silver Spring
- Gaithersburg
- Rockville
- Frederick
- Hagerstown
- Laurel
- Waldorf
- Germantown
- Temple Hills
Is a 301 call a scam?
An area code tells you where a number was first assigned, not where the caller is. Mobile numbers keep their area code when people move, and internet (VoIP) numbers can be picked in any area code — so a 301 number can be calling from anywhere.
Robocallers exploit that with "neighbor spoofing": showing a 301 number to people in Maryland because a local-looking call is more likely to be answered. If a 301 call claims to be your bank, the IRS or a delivery company, hang up and call the official number yourself.
About area code 301
301 is one of the original North American area codes, created in 1947 when AT&T and the Bell System first divided the continent into numbering plan areas.
It is part of the 227/240/301 overlay: the codes cover the same area, and a new line there can be given a number in any of them. Two neighbours — or two phones in one household — can have different area codes. That is also why local calls need the full ten digits.
As the region grew, 227, 240 and 410 were carved out of or added to 301.
Area codes
More area codes in Maryland
All Maryland area codes · Every North American area code · International country codes
FAQ
Area code 301 questions
Sources: NANPA NPA database (11/04/2026) and Google libphonenumber. Area codes show where a number was assigned, not where its owner is today.
Where is area code 301?
Area code 301 is in Maryland, United States. It covers Bethesda, Silver Spring, Gaithersburg, Rockville, Frederick and Hagerstown.
What time zone is area code 301?
301 is in the Eastern (UTC−5) time zone, and observes daylight saving time.
What area codes overlay 301?
240 and 227 serve the same area as 301. Numbers in all of them are local to one another.
When did area code 301 start?
301 entered service in 1947.
How do I find out who called me from 301?
Enter the full number in the lookup at the top of this page. The free check confirms whether the number is valid and shows its carrier, line type and region; a full report adds owner and public-web records where they are available.
Why am I getting calls from area code 301?
If you live in or near Maryland, they may be genuinely local — or robocalls spoofing a local-looking number. Unknown 301 callers who will not leave a message are best looked up before you call back.
Got a call from 301?
Run the free check first — validity, carrier, line type and region — and unlock the full report only if you need it.