The three-digit sequence 663 can refer to an active Mexican area code or a local phone prefix (the middle three digits) within many different North American area codes.
The direct answer is that 663 is the geographic area code for Tijuana, Baja California, Mexico, where it exists as an overlay code for the older 664 area code. However, if you see a full 10-digit number like (256) 663-XXXX, the 663 is the local exchange.
This article clarifies the status of the 663 phone number, explains its use in both Mexico and the US, and provides essential security context.
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Primary Location: Tijuana, Baja California, Mexico
The 663 area code is a valid geographic code (Clave LADA) in Mexico, serving the large border city of Tijuana.
| Detail | Information |
| Area Code (LADA): | 663 (Overlays the 664 code) |
| Country: | Mexico |
| Primary City: | Tijuana, Baja California |
| Full Dialing Code: | +52 663 (where 52 is Mexico’s Country Code) |
| Time Zone: | Pacific Time (PT) (Observes Daylight Saving Time). |
International Dialing to 663
Mexico uses a standard 10-digit national numbering plan. To dial a 663 phone number from the U.S. or Canada, you must use the Mexican Country Code:
(Note: Use of the ‘1’ after the country code is now consolidated into the 10-digit national number.)
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Status in the North American Numbering Plan (NANP)
The sequence 663 is unassigned as a standalone geographic area code in the United States or Canada. However, it is widely used as a phone prefix (NXX).
| Code Use | Example | Location |
| As a Prefix (NXX) | (256) 663-XXXX | Stevenson, Alabama (North Alabama) |
| As a Prefix (NXX) | (570) 663-XXXX | Quaker Lake, Pennsylvania (Northeast PA) |
| As a Prefix (NXX) | (415) 663-XXXX | Point Reyes, California (San Francisco area) |
| As a Code (Short Code) | #663# | Used by T-Mobile as a USSD code (often for disabling Scam ID). |
If you receive a 10-digit call, the number is domestic (US or Canada) and the Area Code (NPA) is the first three digits (e.g., 256, 570, or 415), with 663 simply being the local exchange prefix.
Security and Safety Advice
When dealing with a 663 phone number, be aware of the following security contexts:
- T-Mobile USSD Code: On T-Mobile, the code #663# is a self-service code for turning off Scam ID. Users may inadvertently dial this code instead of #662# (Scam Block) or another code.
- Mexican Scam Risk: Unsolicited calls from +52 663 should be treated as suspicious. Calls from Mexico often involve extortion, fake prize announcements, or phishing.
- Safety Rule: Never answer or return unexpected international calls. If you do not have business in Tijuana, ignore the number.
Frequently Asked Questions (FAQ)
Is 663 a Canadian area code?
No. There is no active or reserved geographic area code 663 in Canada.
What time zone is the Mexican 663 area code in?
The 663 area code (Tijuana) is in the Pacific Time Zone (PT), observing Daylight Saving Time. It is the same time as Los Angeles and Seattle.
What is the simplest way to check if a phone number is a scam?
Use your carrier’s free app (Verizon Call Filter, T-Mobile Scam Shield, AT&T ActiveArmor) or a free online service like Nomorobo or Truecaller to check the number’s spam rating.
Conclusion
The 663 phone number is a valid geographic LADA code for Tijuana, Mexico, but its appearance as a prefix is common in the US (e.g., in Alabama or Pennsylvania). If the number is international, be cautious due to high call costs and potential scams. If you are a T-Mobile customer, remember #663# is a self-service code for managing Scam ID.
