Guam Area Codes
Directory of all 1 telephone area codes assigned to Guam.
Guam phone numbers are served by 1 area code operating in the Chamorro (ChST) timezone.10-digit or 7-digit local dialing applies depending on the exact number. No area codes in Guam are currently flagged as high-risk scams.
Most populated prefix: area code 671 (Guam)
All Area Codes in Guam
Major Cities Served by Guam Area Codes
The most populous urban centers and census places covered by Guam's area codes, ranked by population.
Guam Area Code FAQs
Quick answers to common questions about Guam telephone area codes.
How many area codes does Guam have?
Guam has 1 area codes: 671.
What timezone do Guam area codes use?
Guam area codes operate in the Chamorro (ChST) timezone.
What is the most populated area code in Guam?
Area code 671 is the most populous prefix in Guam based on covered city population.
Does Guam use overlay area codes?
Guam currently has no overlay code pairs listed in our directory.
Are there scam area codes in Guam?
Guam has no area codes currently flagged as high-risk scams.
About Guam Area Codes & Phone Dialing Rules
When placing calls within Guam, ten-digit dialing (area code + 7-digit telephone number) is required in overlay regions where multiple area codes serve the same geographic boundaries.