The 443 area code is an overlay serving eastern Maryland, including Baltimore, Annapolis, and the Eastern Shore. Introduced in 1997, it was the first overlay layered on top of the 410 area code to keep pace with demand for phone numbers across the state’s largest metropolitan region.
Quick Summary of the 443 Area Code
| Area Code | 443 |
| State | Maryland (MD) |
| Region | Baltimore, Annapolis & the Eastern Shore |
| Major Cities | Baltimore, Annapolis, Columbia, Towson, Dundalk, Ellicott City, Glen Burnie, Salisbury, Ocean City |
| Time Zone | Eastern Time (ET) – EST / EDT |
| Dialing Format | 10-digit dialing required |
Geographic Coverage
The 443 area code shares an identical footprint with 410, covering the city of Baltimore and its suburbs of Towson, Dundalk, and Glen Burnie, the Howard County cities of Columbia and Ellicott City, the state capital of Annapolis on the Chesapeake Bay, and the entire Eastern Shore including Salisbury and Ocean City. Because it is an overlay, a 443 number and a 410 number can exist side by side on the same block.
Time Zone
The 443 area code observes Eastern Time (ET). Clocks follow Eastern Standard Time (UTC−5) in winter and shift to Eastern Daylight Time (UTC−4) from mid-March through early November. If you are coordinating a call from the West Coast, remember that this region is three hours ahead of Pacific Time, so a 9:00 AM call in California reaches a 443 number at 12:00 PM local time.
Tip: Business hours across the 443 region generally run 9:00 AM to 5:00 PM Eastern Time, Monday through Friday.
How to Dial a 443 Number
Because area code 443 operates as part of an overlay, 10-digit dialing is mandatory for every local and long-distance call. You must dial the full 10-digit number (443 + the seven-digit line number) even when calling a neighbor across the street. For international callers, dial your country’s exit code, then +1 (the North American country code), then 443, followed by the seven-digit local number.
Scam Alerts for the 443 Area Code
Like every U.S. area code, 443 has been used by scammers who spoof local numbers to appear trustworthy. Residents in Baltimore, Annapolis, Columbia, Towson, Dundalk, Ellicott City, Glen Burnie, Salisbury, Ocean City should stay alert to the following common tactics:
| Scam Type | What to Watch For |
|---|---|
| IRS / Tax Scams | Threatening calls demanding immediate tax payment via gift cards or wire transfer. |
| Utility Shut-off | Impostors claiming to be BGE threatening to cut power unless you pay now. |
| Toll / E-ZPass Scam | Texts claiming you owe an unpaid Maryland toll and linking to a fake payment page. |
| Bank Fraud Alerts | Robocalls impersonating your bank about “suspicious activity” to phish account details. |
If you receive a suspicious call from a 443 number, take these steps to protect yourself:
- Do not share personal information such as Social Security numbers, bank details, or passwords over the phone.
- Hang up and verify by calling the organization back using an official number from its website.
- Report the call to the FTC at reportfraud.ftc.gov and to the Maryland Attorney General’s Office.
- Block the number and consider registering with the National Do Not Call Registry.
Red Flag: Legitimate agencies such as the IRS, Social Security Administration, or your utility company (BGE, Pepco, or Potomac Edison) will never demand immediate payment by gift card, wire transfer, or cryptocurrency. Any 443 caller making such a demand is a scammer.
History and Economy of the 443 Region
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The 443 area code entered service in 1997 as the first overlay for the 410 region, added when Baltimore and eastern Maryland began running short of available numbers. Overlays add a new supply of numbers without forcing existing customers to change their established phone numbers, so 443 covers precisely the same territory as 410 – and, since 2012, the newer 667 overlay as well. The regional economy is powered by the Port of Baltimore, one of the East Coast’s busiest, and by Johns Hopkins University and Hospital, a global leader in medicine and research. Annapolis anchors state government and the U.S. Naval Academy, while Howard County’s technology corridor near Fort Meade drives cybersecurity and defense employment. The Eastern Shore adds agriculture and the seasonal tourism of Ocean City. Many mobile phones and business lines activated since the late 1990s carry the 443 prefix.
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Looking Up a 443 Number
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To identify a 443 caller, use a reverse phone lookup or search the full 10-digit number online. Because 443 is widely used for mobile numbers, a public search may reveal less about the caller, so never share personal or financial details with an unverified 443 number.
Nearby & Related Area Codes
Maryland is served by several area codes. If you are researching 443, these neighboring and overlay codes are worth knowing:
- 410 – Baltimore & Eastern MD (overlay partner)
- 667 – Baltimore overlay (same region)
- 301 – Western MD & DC suburbs
- 240 – DC suburbs overlay
You can also browse our full directory of Maryland area codes for more regional guides.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border Maryland:
- Pennsylvania – area code 215
- Delaware – area code 302
- Virginia – area code 804
- West Virginia – area code 304
Frequently Asked Questions
Where is the 443 area code located?
The 443 area code serves eastern Maryland as an overlay of 410, covering Baltimore, Annapolis, Columbia, and the Eastern Shore including Salisbury and Ocean City.
Why does 443 cover the same area as 410?
443 is an overlay code added in 1997 because the 410 region ran short of available phone numbers. Both codes – along with 667 – serve the exact same region.
Do I have to dial 10 digits for 443?
Yes. Overlay area codes like 443 always require 10-digit dialing for local calls.
Is the 443 area code Eastern Time?
Yes, the 443 area code follows Eastern Time (EST/EDT), like all of Maryland.
Related 443 Guides
- Is a 443 call safe? Read Is area code 443 a scam? Spam & safety guide.
- Local coverage: see the Baltimore area code guide.
- Worried about spam or robocalls? Browse our Scam Alerts directory.