The 551 area code covers the same area as 201, including Hackensack, Jersey City and 24 more places in New Jersey.
Area code 551 is in New Jersey, on Eastern Time. In the 551 area, phone numbers are given out most in Bergen County, then Hudson and Morris counties. It has been in service since December 29, 2001. 201 covers the same area, so two neighbours can have different area codes.
- Where
- 5 counties in New Jersey, mostly Bergen County, Hudson County and Morris County
- Time zone
- Eastern Time
- In service since
- December 29, 2001
- Shares its area with
- 201 (since 1947)
- Prefixes in use
- 300
- How to dial
- Local calls need all 10 digits: 551-555-0142.
Find out who called you from a 551 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (551) number is on today, use our free carrier lookup.
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Jersey City holds 18% of the phone prefixes in area code 551.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 300 prefixes in use shows where 551 numbers are actually given out.
- Jersey City53 prefixes, 18%
- Hackensack47 prefixes, 16%
- Bayonne32 prefixes, 11%
- Union City24 prefixes, 8%
- Ramsey20 prefixes, 7%
- Fair Lawn17 prefixes, 6%
- Cliffside Park14 prefixes, 5%
- Kearny11 prefixes, 4%
Also served: Teaneck, Morristown, Englewood and Bayonne and 14 smaller places.
Of the carriers named here, T-Mobile holds the most phone number prefixes in area code 551: 68 of 300.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 300 prefixes in use in 551 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| T-MobileMobile network | 68 | 23% |
| AT&T MobilityMobile network | 27 | 9% |
| Fractel | 16 | 5% |
| BandwidthSupplies numbers to VoIP and app-based phone services | 15 | 5% |
| Ton80 Communications | 10 | 3% |
| Cablevision Lightpath | 9 | 3% |
| 20 other carriers | 155 | 52% |
99% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
551 started in 2001 as an overlay on 201, and its ground has not changed since.
2001
551 starts on December 29, 2001, as an overlay on 201: new numbers on the same ground.
A 551 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
The area codes closest to 551 are 212, 914 and 973.
This list measures the distance between the centres of each area, across state lines, and shows codes that share one area together.
These are the questions people ask most about area code 551.
Where is area code 551?
551 covers Hackensack, Jersey City, Union City and Rutherford and 22 more places in New Jersey. In the 551 area, phone numbers are given out most in Bergen County, then Hudson and Morris counties.
What state is area code 551 in?
New Jersey. 551 is a New Jersey area code on Eastern Time.
What cities use area code 551?
The places holding the most 551 prefixes are Hackensack, Jersey City, Union City, Rutherford, Ramsey, Fair Lawn, Oradell and Cliffside Park, out of 26 places in all. The count comes from NANPA's prefix assignments as of October 1, 2026.
Which phone company owns area code 551?
No single phone company owns 551. NANPA's records list its 300 prefixes across many carriers, and the ones named on this page include T-Mobile, AT&T Mobility and Fractel. Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 551 in?
551 is on Eastern Time.
When did area code 551 start?
551 went into service on December 29, 2001, as an overlay on 201: new numbers for the same area.
Is 551 the same area as 201?
Yes. 201 (since 1947) covers the same ground as 551. Nobody's number changed when it was added; new lines simply get whichever code has numbers left, so two neighbours can have different codes.
How do I dial a 551 number?
Local calls need all 10 digits: 551-555-0142.
Is 551 a toll-free number?
No. 551 is a regular area code for Hackensack and Jersey City in New Jersey, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
What area codes are near 551?
The closest are 212/718/917/646/347/929/332/465 (New York City, New York), 914 (Westchester County, New York), 973/862 (Newark, New Jersey) and 516/363 (Nassau County, New York), measured between the centres of each area.
Who called me from a 551 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 551 a scam?
551 is a real New Jersey area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.