Guam eSIM Guide

Simple Installation Steps

1. Buy the right plan: a Guam plan, or the USA & Territories regional if your trip also includes the mainland. Not a plain United States plan.
2. Receive the QR code: it arrives by email and in your account straight after payment
3. Install at home: scan the QR code in your phone settings while you are still on your own Wi-Fi
4. Activate on arrival: switch the eSIM line on at Antonio B. Won Pat International and turn on data roaming for that line

eSIM not connecting?

• 1. Turn on airplane mode for 30 seconds, then turn it off
• 2. Make sure data roaming is ON for the eSIM line specifically — this is the single most common cause
• 3. Confirm the eSIM line is set as your mobile data line, not just installed
• 4. If you select a network by hand, choose the one your plan actually carries: Docomo, GTA or IT&E on a per-gigabyte plan, GTA on an unlimited plan. Otherwise leave it on Automatic

Phone showing a US network name or a bare number?

• • Expected. All three Guam operators use MCC 310, shared with the mainland US
• • You may see "310 370" (Docomo Pacific), "310 140" (GTA) or "310 480" (IT&E)
• • As long as data works, nothing is wrong

No signal in the south or inland?

• • Coverage thins along the southern coast road and over the mountain route
• • On a multi-network plan, try selecting a different operator manually before giving up
• • Download offline maps before you set out — the southern loop is the drive where you will want them
• • Signal usually returns at the villages and the main road junctions

Does a United States eSIM work in Guam?

Generally no, and this is the most expensive assumption you can make about Guam. We checked our own coverage data on 12 September 2026: the plans that list Guam are the Guam-specific plans and one regional package called USA & Territories. A plain "United States" eSIM does not carry a Guam entry, because Guam is served by its own operators — Docomo Pacific, GTA and IT&E — and not by AT&T, T-Mobile or Verizon. Buy a Guam plan, or buy the USA & Territories regional if your trip also takes in the mainland, Hawaii, Puerto Rico or the US Virgin Islands.

Guam is a US territory. Does that mean I will not be charged roaming?

It depends entirely on where your own phone plan comes from, and this is where the "US territory" label misleads people. If you are already on a US carrier plan, Guam is normally treated as domestic, the same way Hawaii or Puerto Rico is, so you keep your allowance. If your plan comes from anywhere else — Europe, Latin America, Asia, Australia — Guam is international roaming and the territory status changes nothing at all about your bill. EU "roam like at home" stops at the European Economic Area, so a Spanish or German SIM is billed at an international rate in Guam. That is the case where a local eSIM pays for itself on the first day.

Which network will my Guam eSIM actually connect to?

It depends on which plan you buy, and the difference is real. Our per-gigabyte Guam plans declare three operators — Docomo on 4G, GTA Wireless on 4G and IT&E Wireless on 5G — so the phone can pick whichever is strongest where you are standing. Our unlimited Guam plans declare a single network: GTA, on 4G only. If 5G matters to you, or if you want the phone to have somewhere to fall back to, the per-gigabyte plans are the ones with more than one option. All three operators use MCC 310, the same mobile country code as the mainland United States, so your phone may simply display a US-looking network name.

Can I use my Guam eSIM in Saipan or Palau?

No to both, and they are not the same kind of place. Saipan is part of the Northern Mariana Islands, a separate US commonwealth with its own plans. Palau is not a US territory at all: it is a sovereign country in a Compact of Free Association with the United States, which means US carriers do not treat it as domestic either, and it needs its own eSIM. A Guam plan covers Guam. The USA & Territories regional package covers the mainland, Hawaii, Puerto Rico, the US Virgin Islands and Guam — but not the Northern Marianas and not Palau.

Do I need a passport or visa for Guam?

US citizens travelling from the United States do not need a passport for Guam, though you do need government-issued photo ID and a passport is still the simplest document to travel on. Everyone else does need one, plus permission to enter the United States: an approved ESTA if your country is in the US Visa Waiver Program — Spain and Chile are, and they are the only Spanish-speaking countries on it — or a US visa otherwise. Guam also participates in a second, separate scheme, the Guam-CNMI Visa Waiver Program, which covers twelve Asia-Pacific jurisdictions including Japan, South Korea, Taiwan and Australia. The two programs are not interchangeable, so check which one applies to your passport rather than assuming the one you have heard of.

What time is it in Guam, and why does my calendar keep getting this wrong?

Guam runs on Chamorro Standard Time, UTC+10, with no daylight saving at any point in the year. The part that catches people out is that Guam sits west of the international date line: it is a calendar day ahead of the US mainland, which is why the territory calls itself "Where America’s Day Begins". Flying from Honolulu or Los Angeles you lose a day on the way out and get it back coming home. Set your phone to update the time automatically and double-check the date on anything you have booked before you fly.

How reliable is the network after Typhoon Mawar?

Mawar passed directly over Guam on 24 May 2023 as a Category 4-equivalent typhoon with sustained winds around 140 mph, and the aftermath was a telecom event as much as a wind event: six days later, on 30 May, 163 cell sites were still offline and around 120 more were running on backup power. Almost all of those outages were caused by loss of mains electricity rather than damage to the masts themselves. The networks have been rebuilt and hardened since, and day-to-day service in Tumon, Tamuning and Hagatna is what you would expect of a US-standard network. The practical lesson is about power, not coverage: in typhoon season carry a power bank, keep offline maps downloaded, and remember that an eSIM running on a different operator to the hotel Wi-Fi gives you a second way to reach the outside world.

Will my eSIM work on the military bases?

Around them, yes. Commercial coverage reaches the areas surrounding Andersen Air Force Base and Naval Base Guam, and the villages either side of them. Inside the fence line, access and reception vary with the installation and its own rules, so if you are visiting family on base, ask them rather than relying on a coverage map.

Is there coverage for diving and boat trips?

On land and at the dive shops, yes. Apra Harbor, where the wreck diving is, is a sheltered harbour with the island right there, so boats generally hold a signal near shore; there is obviously nothing underwater. Download your dive site information and any charts before you leave the dock, because the moment you are out past the reef line the signal becomes unreliable.