Guam is a US territory in the western Pacific, the southernmost island of the Mariana chain and, according to its visitors bureau, the largest of more than 2,000 Micronesian islands. Most hotels line Tumon Bay, while Hagåtña, the capital, hosts the Chamorro Village night market every Wednesday evening. Guam is not covered by Roam Like at Home, so a European SIM roams here on its operator's own terms.
Key facts for Guam
- EU roaming: not covered by Roam Like at Home
- Local networks: GTA (depending on the plan)
- Emergency numbers: 911 for the police, an ambulance or the fire service
- Embassies: none; British help comes from the British Consulate General in Los Angeles, and Japan and South Korea have consulates on the island
Two ways in, and a form for everyone
Guam is part of the United States for immigration, so the usual US rules apply: an ESTA under the US Visa Waiver Program, or a US visa. A separate Guam-CNMI Visa Waiver Program lets nationals of 12 countries and territories, including the UK, Australia, Japan and South Korea, stay up to 45 days on Guam and the Northern Mariana Islands only. No EU country is on that list. Since 29 November 2024 the programme requires an electronic travel authorisation, the G-CNMI ETA, issued before departure; the US Department of Homeland Security recommends applying at least 5 days ahead, and approval normally lasts 2 years or until your passport expires. This route also needs a direct trip, without transiting other parts of the US, a return or onward ticket and a passport valid for the whole stay. Whatever your route, every arrival must complete the Guam Electronic Declaration Form, which opens up to 72 hours before landing; one form covers a household, and kiosks in the airport baggage hall serve anyone who could not file it beforehand.
Guam and its neighbours need different plans
The Northern Mariana Islands, just to the north, are a separate territory as far as mobile plans go: the Guam plans do not include them, so a hop to Saipan needs a plan of its own. An Oceania plan covers Guam together with Australia, New Zealand and Fiji, but not the Northern Marianas, and a World plan does not include Guam at all, so check the country list before buying for a multi-stop trip.
Typhoons, earthquakes and tap water
Canada says typhoons usually reach Guam between July and December, and that even small storms can quickly grow into major ones; the UK Foreign Office notes that the Pacific storm season normally runs from May to November and can affect the island. Guam Homeland Security/Office of Civil Defense issues warnings together with the National Weather Service office in Tiyan, and local TV and radio carry its instructions. Guam also lies in an active seismic zone, so earthquakes and tsunamis can occur; if you stay on the coast, learn the evacuation route. After Typhoon Mawar in May 2023, the waterworks authority told residents of some areas to boil their water, so ask your hotel whether the tap water is safe to drink.
Beaches, reefs and wartime remains
Tumon Bay is the busiest beach area, with calm water for snorkelling and paddleboarding, but tidal changes can create powerful currents and riptides are common, so ask locally about safe places to swim. Canada notes that tour operators may not meet international standards, so choose an established, insured dive company. The War in the Pacific National Historical Park, spread over six units, recalls the landings of 21 July 1944, with an overlook above the invasion beach at Asan. Unexploded ordnance from the Second World War can still turn up on beaches, farms, building sites and dive spots: never touch war remnants, stay away from reported wrecks, and alert the authorities.
Roads, buses and the law
Traffic drives on the right. Main roads are paved but can be poorly maintained and lit, there are no pavements outside the central districts of Hagåtña and Tamuning, roads in the south flood easily in the rainy season, and stray animals wander onto the tarmac. Canada tells its citizens to carry an International Driving Permit. Buses exist but are slow and unreliable; taxis are generally safe, though some drivers overcharge, so use marked cabs and agree the fare or ask for the meter. Small amounts of cannabis are legal under Guam law but remain illegal under US federal law, and penalties for other drugs are severe.
Healthcare and money
Canada rates medical services as very good and widely available, but as elsewhere in the US, treatment is expensive and some hospitals ask non-residents for a deposit, so take insurance that includes medical evacuation. Dengue occurs sporadically. The currency is the US dollar, and there is no general sales tax.
Getting connected
A travel eSIM set up before your flight connects as soon as you land. The Guam plans run on GTA, with 5G where available, and an Oceania plan suits a trip that continues to Australia, New Zealand or Fiji. Leave your home SIM in place for bank codes, but turn its data roaming off.
Consular protection: who to call in Guam
- Call 911 in any emergency, whether you need the police, an ambulance or firefighters.
- Guam is a US territory, so there are no embassies: British nationals are covered by the British Consulate General in Los Angeles, and Canadians by the Consulate General of Canada in San Francisco.
- Japan and South Korea both have consulates general in Hagåtña.
- Look up in the Telcomia app the consulate that covers Guam for your nationality, and save its number before you fly.
- If your EU country has no representation for Guam, the embassy or consulate of any other EU country must help you on the same terms as its own nationals (Article 23 of the Treaty on the Functioning of the EU).
- English and CHamoru are the official languages.
Questions travellers ask about Guam
Will my EU SIM work in Guam?
Only on roaming at your operator's own rates, because Guam is outside Roam Like at Home.
Can I use the Guam-CNMI visa waiver?
Only with a passport from one of the 12 participating countries and territories, such as the UK, Australia, Japan or South Korea. EU passport holders need an ESTA or a US visa.
Which network does a Telcomia eSIM use in Guam?
GTA, with 5G where available.
Does my Guam plan work in Saipan?
No. The Northern Mariana Islands need a plan of their own.
The short version
Pick your entry route early, get the ESTA or the G-CNMI ETA in advance, file the declaration form within 72 hours of landing, install the eSIM before you fly, add a separate plan for Saipan, follow typhoon warnings, leave war relics alone, carry insurance, and save 911.
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