Area code 551 is a New Jersey area code that covers Hudson County and Bergen County in the northeastern corner of the state. It is an overlay of area code 201, which means 551 and 201 serve the same area, including Jersey City, Hoboken, Bayonne, Secaucus, Hackensack and Englewood. Area code 551 went into service on December 1, 2001, and since then everyone in the region has had to dial all 10 digits for local calls.
Key Takeaways
- Area code 551 is an overlay of 201, so both codes serve the same towns.
- Coverage: Hudson and Bergen counties in North Jersey.
- Start date: area code 551 began on December 1, 2001.
- 10-digit dialing has been required in the 201/551 region since the overlay began.
- A 551 number is a regular New Jersey number, used by both landlines and cell phones.
- Area code 201 dates to 1947 and was one of the original North American area codes.
Dates and coverage follow numbering history records reviewed in September 2026.
Area Code 551 Quick Facts
| Fact | Details |
|---|---|
| State | New Jersey |
| Counties | Hudson and Bergen |
| Type | Overlay of area code 201 |
| In service since | December 1, 2001 |
| Dialing | 10 digits (area code + number) for local calls |
| Time zone | Eastern Time |
| Parent area code | 201 (created in 1947) |
Where Is Area Code 551?
Area code 551 serves the same territory as 201: Hudson County and Bergen County. This is the most densely settled part of New Jersey, directly across the Hudson River from Manhattan. Major cities and towns include:
| County | Cities and towns in area code 551 and 201 |
|---|---|
| Hudson County | Jersey City, Hoboken, Bayonne, Union City, West New York, North Bergen, Secaucus, Weehawken, Kearny |
| Bergen County | Hackensack, Englewood, Fort Lee, Paramus, Teaneck, Ridgewood, Fair Lawn, Mahwah |
Because 551 is an overlay, you cannot tell which of these towns a number belongs to from the area code alone. In addition, many people keep their cell phone numbers when they move, so a 551 number may belong to someone living elsewhere.
Why Area Code 551 Was Created
Area code 201 was established in 1947 as one of the original area codes in North America, and it first covered all of New Jersey. Over time, growing demand for phone numbers led to several changes:
| Year | Change |
|---|---|
| 1947 | Area code 201 created, covering the whole state |
| 1956 | Area code 609 created for southern New Jersey |
| 1991 | Area code 908 split off north-central New Jersey |
| 1997 | Area code 973 split off Essex, Passaic, Morris and Sussex counties |
| December 1, 2001 | Area code 551 added as an overlay for the remaining 201 area |
After the 1997 split, experts expected 201 to last for many years. However, demand from cell phones, pagers and fax lines used up the remaining numbers within about four years. As a result, regulators chose an overlay instead of another split, so existing customers could keep their numbers.
Area Code 551 and 10-Digit Dialing
With an overlay, two area codes share the same area, so the phone system needs the full number to know where to connect a call. That is why 10-digit dialing began in the 201/551 region when area code 551 started in 2001. Today, every New Jersey area code requires 10-digit dialing for local calls.
- Local calls: dial the area code plus the seven-digit number, such as 551-555-0123.
- Long-distance calls: dial 1, the area code and the number.
- Update saved contacts and devices such as alarm systems to include the area code.
Is a 551 Call a Scam?
A call from area code 551 is a normal New Jersey call. However, scammers can fake any caller ID, including local area codes, a trick known as spoofing. Be careful with unexpected calls that:
- Ask for payment by gift card, wire transfer or cryptocurrency.
- Claim to be from a government agency and demand immediate payment.
- Ask for passwords, Social Security numbers or bank details.
- Pressure you to act right away.
If a call seems suspicious, hang up and call the organization back using a number from its official website or your bill.
Area Code 551 vs. Other North Jersey Area Codes
| Area code | Main area | Overlay partner |
|---|---|---|
| 201 / 551 | Hudson and Bergen counties | Each other |
| 973 / 862 | Essex, Passaic, Morris and Sussex counties | Each other |
| 908 | Union, Somerset, Hunterdon and Warren counties (parts) | None |
| 732 / 848 | Central Jersey, including Middlesex and Monmouth | Each other |
Getting a 551 Phone Number
When you open a new phone line in Hudson or Bergen County, your carrier assigns a number from whatever codes it has available for that area. Today, new numbers are often in area code 551 because many 201 numbers are already in use. Some carriers let you pick from a few options, and number porting lets you keep an existing number when you switch carriers.
About the 201 and 551 Region
The area code 551 region is home to a large share of New Jersey’s population. Bergen County has about 977,000 residents and Hudson County about 735,000, according to recent Census estimates, so the two counties together are home to roughly 1.7 million people. As a result, demand for phone numbers remains high, especially for cell phones and business lines.
The region includes busy commuter towns along the Hudson River, such as Jersey City, Hoboken, Weehawken and Fort Lee, as well as suburban Bergen County communities like Paramus, Ridgewood and Mahwah. Because the region sits directly across from Manhattan, many residents commute to New York City by PATH, bus, ferry or car.
Area Code 551 for Businesses
- Local presence: a 201 or 551 number signals a North Jersey business to local customers.
- Keeping your number: you can usually port an existing number when switching carriers.
- Mixed codes: offices may have some lines in 201 and others in 551, since both serve the same area.
- Print full numbers: always include the area code on signs, websites and business cards.
History of Overlays in New Jersey
When the 201 region ran short of numbers in the late 1990s, regulators faced a choice. They could split the region again, forcing many customers to change numbers, or add a second code on top of the same map. They chose the overlay approach. Since then, overlays have become the standard way to add capacity in New Jersey. For example, 862 overlays 973, 848 overlays 732 and 640 overlays 609. As a result, almost every part of the state now has two area codes sharing the same territory, and residents across New Jersey dial 10 digits for local calls.
Overlays have one big benefit: nobody has to give up an existing number. The trade-off is that you can no longer guess a caller’s exact location from the code alone.
For most residents, the practical takeaway is simple: save every contact with its full 10-digit number, including the code, and do not assume a caller is nearby just because the code looks local. Businesses should also list complete numbers on websites and signs.
If you have more questions, your phone carrier can explain which area codes it offers for new lines in Hudson and Bergen counties.
More New Jersey Area Code Guides
See our complete guide to NJ area codes for every code in the state. For Central and South Jersey, read our guides to area code 732 and area code 856. To learn more about the region, explore our list of counties of NJ. Browse more in our Living in NJ section or on the homepage.
Frequently Asked Questions About Area Code 551
Where is area code 551?
Area code 551 covers Hudson and Bergen counties in northeastern New Jersey.
Is 551 the same as 201?
Yes. 551 is an overlay of 201, so both codes serve the same area.
When did area code 551 start?
Area code 551 went into service on December 1, 2001.
What cities use area code 551?
Cities include Jersey City, Hoboken, Bayonne, Secaucus, Hackensack, Englewood and Fort Lee.
Do I need to dial 10 digits in area code 551?
Yes. 10-digit dialing has been required in the 201/551 area since the overlay began.
Is a call from 551 a scam?
A 551 call is a normal New Jersey number, but scammers can spoof any caller ID, so be cautious with unexpected requests for money or personal information.
What area code was used before 551?
Area code 201 served the region alone until the 551 overlay was added on December 1, 2001.
Is 551 a cell phone area code?
No. Area code 551 is used for both landlines and cell phones in Hudson and Bergen counties.
What time zone is area code 551?
Area code 551 is in the Eastern Time Zone.
The Bottom Line
Area code 551 is the overlay for 201, serving Hudson and Bergen counties, including Jersey City, Hoboken and Hackensack. It began on December 1, 2001, when 10-digit dialing became required in the region. A 551 number is a standard New Jersey number, but as with any area code, be cautious with unexpected calls asking for money or personal information.
