How To Call Guam From US: Updated For 2025
Quick Answer
To call Guam from the United States (Guam is part of the North American Numbering Plan - NANP):
- Landline or Mobile:
1 + 671 + Guamanian Number (7 digits)
Examples:
- For a Guam landline (e.g., starting with 472):
1 + 671 + 472 XXXX - For a Guam mobile phone (e.g., starting with 688):
1 + 671 + 688 XXXX
Guam is on Chamorro Standard Time (ChST), UTC+10. This is 14-15 hours ahead of US Eastern Time (ET), depending on US DST. Guam does not observe daylight saving.
How to Dial Guam from the US
Guam is a U.S. territory and part of the North American Numbering Plan (NANP). This means calling Guam from the US is like making a long-distance call to another US state, not like typical international dialing that uses an exit code like `011`.
How to Call a Landline in Guam
To call a Guamanian landline from the United States:
- Step 1 – Dial
1: This is the US long-distance dialing code (also used for NANP calls). - Step 2 – Dial Guam's Area Code: Next, key in
671. This is the specific area code for Guam within the NANP. - Step 3 – Dial the 7-digit local landline number: All local phone numbers in Guam are 7 digits long.
For example, to call a Guam landline number 472 1234, you would dial: 1 671 472 1234
How to Call a Mobile Phone in Guam
Calling a Guamanian mobile phone from the US also follows the NANP format:
- Step 1 – Dial
1: This is the US long-distance dialing code. - Step 2 – Dial Guam's Area Code: Next, key in
671. - Step 3 – Dial the 7-digit local mobile number: Guam mobile numbers are 7 digits long.
For example, if the Guam mobile number is 688 9876, you would dial: 1 671 688 9876 from the US.
Understanding Guamanian Phone Numbers
Guam uses the area code 671 as part of the North American Numbering Plan. When calling from the US, you dial 1 followed by 671 and then the 7-digit local number.
Landline & Mobile Numbers
- Format from US:
1 + 671 + XXX XXXX(7-digit number) - All local numbers in Guam are 7 digits long.
- There are no further city-specific area codes within Guam after dialing
671. The first three digits of the 7-digit number (NXX, or Central Office Code) indicate the specific exchange.
Guam Numbering Plan (NANP)
Guam is part of the North American Numbering Plan (NANP) and uses area code 671 for the entire territory. All local phone numbers are 7 digits long, typically formatted as NXX-XXXX, where NXX is the central office code.
Examples of central office code prefixes (first 3 digits of the 7-digit number) and their general locations/associations:
| NXX Prefix (of 7-digit number) | General Location / Association |
|---|---|
3XX | U.S. Military |
47X | Hagåtña, Agana Heights, Asan-Maina, Piti, Chalan-Pago-Ordot, Mongmong-Toto-Maite |
56X | Agat, Santa Rita |
63X | Dededo |
64X | Tamuning |
65X | Yigo |
73X | Mangilao, Barrigada |
789 | Yona, Talofofo |
828 | Merizo, Inarajan, Umatac |
969 | DoCoMo Pacific mobile subscribers |
68X, 7XX, 9XX (various) | Generally Mobile services from providers like GTA, IT&E, Docomo Pacific |
Note: With number portability, these prefixes may not always indicate the original service or provider. Since October 2021, 10-digit dialing (1-671-XXX-XXXX) is required even for local calls within Guam due to the implementation of 988 as a national suicide prevention lifeline.
Guamanian Mobile Phone Indicators
As part of the 7-digit numbering plan under the +1-671 area code, mobile numbers in Guam are 7 digits long and use various NXX prefixes. You dial the full 1 + 671 + NXX XXXX.
Common mobile prefixes are often within the 6XX, 7XX, and 9XX ranges, but this can vary by provider (GTA, IT&E, Docomo Pacific, etc.).
Time Difference
Guam operates on Chamorro Standard Time (ChST), which is UTC+10. Guam does not observe Daylight Saving Time.
The time difference compared to the US East Coast (ET):
- When the US East Coast is on Eastern Daylight Time (EDT, UTC-4): Guam is 14 hours ahead of ET. (e.g., 12 PM Tuesday EDT is 2 AM Wednesday in Guam).
- When the US East Coast is on Eastern Standard Time (EST, UTC-5): Guam is 15 hours ahead of ET. (e.g., 12 PM Tuesday EST is 3 AM Wednesday in Guam).
Guam's Phone System
Guam, as a U.S. territory, has a highly connected and progressive telecommunications sector. It is part of the North American Numbering Plan (NANP) with area code 671. The system features robust international connectivity via multiple submarine fiber optic cables, making it a telecom hub in the Pacific. Major service providers include GTA Teleguam, Docomo Pacific, and IT&E, offering fixed-line, mobile (with 3G/4G LTE and expanding 5G), and broadband internet services. The Federal Communications Commission (FCC) regulates calls to and from Guam as domestic for U.S. carriers.
Best Times to Call
Considering Guam is 14-15 hours ahead of US Eastern Time (ET):
- Calls from the US ET zone are best made in the evening to align with Guam's morning the next day. For example, 6 PM - 9 PM ET on a Monday would correspond to 8 AM - 11 AM or 9 AM - 12 PM on Tuesday in Guam.
- Guam's business hours are typically Monday to Friday, from around 8:00 AM to 5:00 PM ChST.
Call Guam For Less With Phone Card Choice
Connect with friends, family, or business contacts in Guam affordably. Our selected phone cards offer great rates and clear connections for your calls. (Note: Phone cards often require dialing the full international sequence: 011 + 1 + 671 + 7-digit number after the access number and PIN).
Asia Call Phone Card: Guam Landlines
3¢/min
Connection Fee: Nil | Billing Increment: 2 minutes
Pricing Tiers:
| Price | Talk Time |
|---|---|
| US$ 10.00 | 5h 33min |
| US$ 20.00 | 11h 5min |
| US$ 50.00 + US$5.00 bonus | 30h 33min |
Rates are subject to change. Please check the latest rates.
Star Phone Card: Guam Mobiles
2.8¢/min
Connection Fee: Nil | Billing Increment: 3 minutes
Pricing Tiers:
| Price | Talk Time |
|---|---|
| US$ 10.00 | 5h 55min |
| US$ 20.00 | 11h 52min |
| US$ 30.00 + US$3.00 bonus | 19h 37min |
Rates are subject to change. Please check the latest rates.
Why Choose Our Calling Cards?
Simple Steps to Call (using a Phone Card):
- Dial the local access number provided with your card.
- Enter your 10-digit PIN number.
- Dial the full international number for Guam:
011 + 1 + 671 + Guamanian Number(7-digit number).
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