The 939 area code serves the entire U.S. territory of Puerto Rico, including major cities like San Juan, Ponce, and Bayamón. It operates as an overlay for the original 787 area code, meaning both codes serve the same geographic area and are used interchangeably for new phone numbers.
If you have seen a phone number with a 939 prefix, this guide will explain its location, the history behind its creation, and how to properly dial a number in Puerto Rico from the United States mainland.
Where is the 939 Area Code Located?
The 939 area code is located exclusively in the Commonwealth of Puerto Rico, a U.S. territory in the northeastern Caribbean Sea. Unlike many area codes that are split geographically, the 939 code was added as an “overlay” to the existing 787 area code, covering the whole island.
- Location: Puerto Rico (U.S. Territory)
- Major Cities: San Juan, Bayamón, Carolina, Ponce
- Time Zone: Atlantic Standard Time (AST). Importantly, Puerto Rico does not observe daylight saving time, so its time is UTC-4 year-round.
What Cities and Municipalities Use the 939 Area Code?
Because the 939 area code covers the entire island alongside 787, a number with this prefix could be located in any of Puerto Rico’s 78 municipalities. The most populated areas include:
Major Municipalities in Area Code 939:
- San Juan (the capital city)
- Bayamón
- Carolina
- Ponce
- Caguas
- Guaynabo
- Mayagüez
History of the 939 Area Code and 10-Digit Dialing
Puerto Rico was originally assigned the 787 area code in 1996. Due to the rapid growth in demand for cell phones and new phone lines, the supply of available 787 numbers began to run out.
To address this, the 939 area code was officially put into service in 2001 as an overlay. This modern solution allowed existing 787 phone numbers to remain unchanged while providing a new pool of 939 numbers for new customers.
A key result of this overlay plan is that mandatory 10-digit dialing is in effect for all local calls within Puerto Rico. You must dial the area code (either 787 or 939) followed by the seven-digit number, even when calling a neighbor.
How to Call a Number in Puerto Rico
Because Puerto Rico is part of the North American Numbering Plan (NANP), calling a 939 number from the United States or Canada is simple and is treated as a domestic long-distance call.
Follow this format:
- Dial 1 (the U.S. country code).
- Dial the area code (either 939 or 787).
- Dial the seven-digit local phone number.
The complete sequence is: 1 + 939 + [Seven-Digit Phone Number]
Important: You do not need to use an international exit code like 011.
Frequently Asked Questions
Is a call to the 939 area code an international call?
No. From the United States mainland, a call to Puerto Rico (area code 939 or 787) is considered a domestic long-distance call, not an international one. However, it’s always wise to check with your specific phone carrier, as some plans may have different rates for calls to U.S. territories.
What is the difference between area codes 939 and 787?
Geographically, there is no difference. Both area codes serve the entire island of Puerto Rico. The only distinction is when the phone number was assigned; 939 numbers were issued to new customers starting in 2001.
What time zone is area code 939?
The 939 area code is in the Atlantic Standard Time (AST) zone (UTC-4). Puerto Rico does not observe daylight saving time, so the time remains the same year-round.
Is the 939 area code a scam?
No, 939 is a legitimate and official area code for the U.S. territory of Puerto Rico. However, like any valid area code, it can be “spoofed” or used by scammers. You should always be cautious when answering calls from numbers you do not recognize.
Conclusion
In summary, the 939 area code is an overlay that serves the same region as the 787 area code, covering the entire island of Puerto Rico. Calls to this U.S. territory from the mainland are considered domestic, and mandatory 10-digit dialing is required for all local calls. It represents a key part of the telecommunications infrastructure for millions of American citizens in the Caribbean.
