Home phone number Guam
Guam Phone Number validator
How the phone number format works
- Format
- Guam phone number in national or international (+1) format
- Example
- +16713001234
Things to watch for
- Accepts national or international (E.164, e.g. +1...) format
- Validated with Google's libphonenumber; confirms the number is possible/valid for this country, not that it is currently assigned or reachable
^[+]?[0-9 ()\-]{6,}$Guam, an unincorporated US territory in the western Pacific, uses area code 671 within the standard NANP +1 plan — the same 10-digit shape as a mainland US number, just geographically about as far from Washington DC as it’s possible to get while still being American soil. Home to the indigenous Chamorro people and a major US military presence at Andersen Air Force Base and Naval Base Guam, the island also markets itself as “Where America’s Day Begins,” owing to its position just west of the International Date Line.
How this validator works
Enter the number in local form (671-300-1234) or full international form (+16713001234); this tool checks the digit count and confirms the area code matches 671, Guam’s assigned NANP code, using Google’s libphonenumber entirely client-side. As with any NANP territory, the area code — not the shared +1 prefix — is what actually pins the number to Guam rather than to one of the dozens of other countries and territories in the same numbering plan.
What a pass doesn’t tell you
A pass confirms the number carries the genuine Guam area code and a plausible local number — it does not confirm the line is connected, ported, or still held by whoever gave it to you.
Scope: format and area-code-origin validation only, for catching a mistyped digit before a number reaches a CRM or dialer — not a substitute for a carrier lookup.
Content last reviewed 2026-08-09.
phone number FAQ
Why does Guam brand itself 'Where America's Day Begins'?
Because of its position just west of the International Date Line, Guam is typically the first place on US soil to see each new day — a slogan with nothing to do with its phone system, which runs on the same NANP +1 plan as the rest of the country, via area code 671.
Why does Guam show up so often in US military contexts?
It hosts two major installations, Andersen Air Force Base and Naval Base Guam, making it a key US military hub in the western Pacific — a significant share of 671-area-code numbers trace back to military personnel and contractors stationed there.
Does a valid 671 number confirm the SIM is currently active?
No. It only confirms the area code and 7-digit local number match a real Guam NANP pattern — not that the line is active or reachable, which needs a carrier-side lookup this tool doesn't perform.