443 area code
Baltimore area, Eastern Time.Area code 443 covers Baltimore, Annapolis, Towson and 99 more places in Maryland, on Eastern Time. 410 and 667 cover the same area.
Right now in Baltimore
Eastern Time (EST, UTC-5; EDT, UTC-4 in summer)
Calling hours: Every day, 8 AM to 8 PM (Maryland law)
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Where 443 numbers come from
Numbers are issued by rate center, a billing area named for its main town. 443 has 102. Each one's share is how many 443 numbers start there. Its biggest metro area is Baltimore-Columbia-Towson, MD.
- Baltimore24%
- Annapolis5%
- Towson4%
- Columbia4%
- Glen Burnie3%
- Catonsville3%
- Pikesville3%
- Salisbury3%
- Bel Air2%
Also: Aberdeen, Westminster, Parkville, Cockeysville, Essex, Elkton, Woodlawn, Severna Park, Arbutus, Dundalk, Fallston, Elkridge + 81 more
Share of exchanges (blocks of 10,000 numbers). Source: NANPA rate center and exchange reports, November 10, 2026
When can you call a 443 number?
Sales calls to homes and cell phones have legal hours, set by Maryland law. Hold every 443 number to them, since you can't tell a work line from a personal cell.
What applies to 443Every day, 8 AM to 8 PM
- Federal (TCPA and FTC rule)Every day, 8 AM to 9 PMCalls to residential and mobile numbers. Most calls to businesses are exempt from the FTC's rule.47 CFR 64.1200(c)(1); 16 CFR 310.4(c) (opens in a new tab)
- Maryland lawEvery day, 8 AM to 8 PMAlso no more than 3 calls in 24 hours on the same subject.Md. Code, Com. Law 14-4502(c) (opens in a new tab)
Local time comes from the area code, not from where the person is today. Mobiles keep their number when they move. Calling hours here are a guide, not legal advice. Every state's calling hours, with sources
443 and 410 and 667
443 went into service on June 1, 1997. 443, 410 and 667 cover the same area, so new numbers can get any of them and neighbors can have different area codes. 443 holds 39% of the area's exchanges, the most of any code here. Local calls take all 10 digits.
- 1991410 overlay
- 1997443 starts
- 2012667 overlay
Source: NANPA area code database
Other Maryland area codes
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443 area code FAQ
What area code is 443?
443 is a Maryland area code for Baltimore, Annapolis, Towson, Columbia and 98 more places.
What time zone is the 443 area code in?
Eastern Time (EST, UTC-5; EDT, UTC-4 in summer).
Is 410 the same as 443?
Same area, different code. 443, 410 and 667 cover the same area (an overlay), so new numbers can get any of them and local calls take all 10 digits.
What are the calling hours for 443 numbers?
Every day, 8 AM to 8 PM, local time, under Maryland law.
When did the 443 area code start?
On June 1, 1997.
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