Guam phone number format
How do you format a Guam phone number?
Write a Guam phone number with the country code +1. A mobile looks like (671) 300-1234 inside Guam and +1 671 300 1234 from abroad. Mobiles have 10 digits after the country code, and the E.164 form is +16713001234. A format check confirms the digits fit the numbering plan, not that the number is in service.
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Paste your Guam numbers (a mixed list is fine). They are counted here at once; the free checker then gives every number its E.164 form, country and line type, with a file to download.
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See the phone add-onGuam number format at a glance
| Country calling code | +1Shared with American Samoa, Anguilla, Antigua & Barbuda, Bahamas, Barbados, Bermuda, British Virgin Islands, Canada, Cayman Islands, Dominica, Dominican Republic, Grenada, Jamaica, Montserrat, Northern Mariana Islands, Puerto Rico, Sint Maarten, St. Kitts & Nevis, St. Lucia, St. Vincent & Grenadines, Trinidad & Tobago, Turks & Caicos Islands, U.S. Virgin Islands, United States |
|---|---|
| International prefix (calling out of Guam) | 011 |
| Trunk prefix (domestic dialling) | None |
| Mobile number length | 10 digits after +1 |
| Landline number length | 10 digits after +1 |
| Mobile vs landline from the digits | Not reliably, many ranges are shared |
In short: +1, 10 digits for a mobile. The checker below formats any Guam number free in your browser; it can't say whether a line is live. Bulk phone number validator · Pro + Phone plan
Example Guam phone numbers
These are the example numbers from Google’s libphonenumber data, the same numbering-plan data our validator uses, written three ways.
| Format | Mobile | Landline |
|---|---|---|
| National (inside Guam) | (671) 300-1234 | (671) 300-1234 |
| International | +1 671 300 1234 | +1 671 300 1234 |
| E.164 | +16713001234 | +16713001234 |
How to write a Guam number in E.164
- Remove spaces, dashes, dots and brackets so only digits are left.
- Guam has no trunk prefix, so keep every digit of the national number.
- Put +1 in front. The result has 10 digits after the country code for a mobile.
So (671) 300-1234 becomes +16713001234. E.164 is the format SMS gateways, dialers and most CRMs store; see the E.164 format explained for why.
Mobile or landline?
In Google’s numbering-plan data, many Guam ranges are listed as “fixed line or mobile”, so the digits alone can’t always say whether a number takes texts. A live carrier lookup asks the network which kind of line serves the number now. More in mobile vs landline lookup.
Mobile, landline and special number ranges in Guam
Google's data lists no separate mobile range for Guam, so mobiles and landlines share the same digits. Every valid number of each type below starts with one of the digit groups shown. A number that starts the right way can still be unassigned: the groups say what a range is for, not that a number is connected.
| Type | Starts with, after +1 | Digits | Example |
|---|---|---|---|
| Landline (fixed line) | 6712–6719 | 10 | +1 671 300 1234 |
| Toll-free | 8002–8009, 8332–8339, 8442–8449, 8552–8559, 8662–8669, 8772–8779, 8882–8889 | 10 | — |
| Premium rate | 9002–9009 | 10 | — |
| Personal number | 500, 521–529, 532, 533, 544, 566, 577, 588 | 10 | — |
More on Guam’s free-to-call and charged ranges: toll-free and premium numbers in Guam.
Sources, checked 5 November 2026
- Ranges, lengths and examples: Google libphonenumber numbering-plan data (libphonenumber-js 1.13.15), the data our validator uses.
- Official plan: ITU-T E.164 national numbering plan for Guam. The regulator’s filing is the authority when the two disagree.
Validate a list of Guam numbers
Check a single number with the free phone number validator. For a whole file, upload the CSV to the verifier: every row gets a status, the E.164 number, the country and the line type, and emails in the same file get a live mailbox check. The Pro + Phone plan ($49.99 a month) adds 5,000 live carrier lookups a month for the real line type and current carrier.
Common questions
- What is the country code for Guam?
- The country calling code for Guam is +1. It is shared with 24 other countries and territories, so the number after it decides which one a number belongs to. When you call Guam from abroad, dial your international prefix (or +) followed by 1 and the number.
- How many digits is a Guam phone number?
- A Guam mobile number has 10 digits after the country code +1, the same as a landline.
- How do I write a Guam number in international format?
- Start with +1, then add the rest of the number. The mobile number (671) 300-1234 becomes +1 671 300 1234, or +16713001234 in E.164, the form most CRMs and SMS tools expect.
- Can you tell if a Guam number is a mobile?
- Not always from the digits. In Google's numbering-plan data many Guam ranges are listed as "fixed line or mobile", so the number alone doesn't settle it. A live carrier lookup asks the network which kind of line serves the number today.
- Does a valid format mean a Guam number is in service?
- No. A valid format means the digits fit a range Guam's numbering plan allocates. It cannot tell whether the number is connected today or who carries it, because numbers are reassigned and ported. A live carrier lookup reports the current carrier and line type, but even that does not prove someone answers.
- Can I check a list of Guam numbers for free?
- Yes. Paste them in the list tab above or upload a CSV to the bulk phone number validator: E.164, country, format status and numbering-plan line type are free for every row, with no account. Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month).
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