eSIM California from €2.46

Name: eSIM California
Brand: HelloRoam

HelloRoam is a global eSIM provider offering instant mobile data in 185+ countries. Buy prepaid travel eSIM plans with no extra fees, no contracts, and instant activation on any eSIM-compatible device.

A California eSIM from HelloRoam starts at €2.46 across 204+ carrier networks in 185+ countries. Activate via QR code in under two minutes on any eSIM compatible phone. Your Three Ireland, Vodafone IE, or Eir number stays active on dual SIM.

194+
local networks
5G
5G support
2 minutes
to activate

Last updatedMay 2026

California eSIM coverage and activation

Cheap eSIM for California, starting from €2.46. Local 4G LTE and 5G data on top carrier networks in California. Works on all eSIM compatible phones. A California road trip is on many an Irish traveller's bucket list: LA's Hollywood and Venice Beach, San Francisco's Golden Gate and Fisherman's Wharf, Big Sur's coastal cliffs, and Napa's vineyards. An eSIM in California from HelloRoam starts at €2.46 and covers the full state on US networks. Activate by QR code at home before flying from Dublin. No roaming charges, no contract. 180-day refund guarantee, GDPR-compliant checkout.

California eSIM with fast 5G coverage

HelloRoam offers eSIM plans for California starting from $2.87. Connect on 5G through T-Mobile and AT&T. Your Irish carrier's international roaming charges apply outside the EU. A HelloRoam eSIM costs far less than daily roaming add-ons from Eir, Three Ireland, or Vodafone Ireland. Activate before your flight from Dublin Airport and connect on arrival at Los Angeles International Airport or San Francisco International Airport.

Plans start at €2.46 with 5G speeds
Coverage from T-Mobile and 2+ other operators
Instant activation in under 2 minutes
180-day money-back guarantee
California coverage across major cities

Network: 5G
Plans From: €2.46
Activation: Under 2 min
Guarantee: 180 days

Trip changed? No bother, we have got you sorted.

Plans change, and that is no bother at all. With HelloRoam, you can request a full refund for your eSIM within 180 days of purchase.

Learn more about our refund policy

HelloRoam California eSIM vs Three Ireland, Vodafone IE and Eir roaming

Comparing eSIM vs a travel SIM card for California? Eir charges up to €5.99/day for Worldwide Roaming, Vodafone IE up to €6.99/day for Global Roaming, and Three Ireland applies daily charges outside its Go Roam zone. Skip the airport SIM counter at Dublin Terminal 1 and get a prepaid eSIM from €2.46 with instant QR activation and a six-month money-back guarantee.

HelloRoam California eSIM vs Three Ireland, Vodafone IE and Eir roaming
Feature		Irish carrier roaming add-on	Limited data eSIM
180-day refund policy
24/7 live chat support
€0 activation fees
99.8% uptime guarantee
No data overage charges
Instant QR code delivery
Premium California carrier networks

Why Travellers from Ireland Use HelloRoam e-sim for California

HelloRoam vs Other eSIM Providers for California

eSIM provider reviews from Irish travellers consistently highlight the 180-day refund policy, zero activation fees, and 24/7 live support. See how HelloRoam compares to Airalo, Holafly, Saily, and other eSIM providers on the things that matter most for your California holiday.

Feature comparison
Feature comparison		Airalo	Holafly	Nomad	Saily	Ubigi
180-day refund policy
24/7 live chat support
€0 activation fees
99.8% uptime guarantee
No data overage charges
Instant QR code delivery
Premium California carrier networks
Own branded carrier identity (SPN)

California — mobile connectivity coverage

Mobile connectivity guide for California

California has 5G mobile coverage across its main tourist areas. T-Mobile and AT&T are the core networks. Your Irish carrier's international roaming charges apply outside the EU. A HelloRoam eSIM costs far less than daily roaming add-ons from Eir, Three Ireland, or Vodafone Ireland.

A HelloRoam eSIM means you arrive at Los Angeles International Airport or San Francisco International Airport already connected without hunting for a SIM card. Plans start at $2.87.

HelloRoam connects to T-Mobile 5G, Verizon 5G, AT&T 5G in California
5G coverage across California's main areas
Connect on T-Mobile and AT&T
Activate before your flight from Dublin

eSIM Travel Tips for California

Sort your eSIM before you leave Dublin
Buy your HelloRoam eSIM for California at home, scan the QR code over Wi-Fi, and switch on data when you land at Los Angeles International Airport or San Francisco International Airport. You step off the plane already connected on local 5G. No queuing at airport telecom shops.
Keep your Irish number live
On a dual-SIM phone, leave your Three Ireland, Vodafone Ireland, Eir, or GoMo SIM active for calls and texts. Use HelloRoam for data in California. People back home can still ring your Irish number without international charges.
Download offline maps first
Save Google Maps or Maps.me for California offline before you fly. Offline navigation uses no data and keeps working even where signal is patchy. It's a handy backup when you arrive and need directions quickly.
Watch your data usage
The HelloRoam app shows your balance in real time. You get alerts at 80% and 95% usage so there are no nasty surprises. Top up inside the app if you need more data in California, no reinstall needed.
Save emergency numbers offline
The emergency number in most countries is 112. In California it is worth checking the local number too. Save these offline before you travel. Emergency calls work on any available network regardless of your HelloRoam data balance.

Mobile networks in California: what Irish visitors need to know

HelloRoam connects on T-Mobile and AT&T in California. These are the leading 5G networks with strong coverage in Los Angeles, San Francisco, and San Diego and main tourist areas. Your eSIM picks the best available signal automatically. Plans start at $2.87 and give you instant 5G data on arrival.

T-Mobile: 5G
Verizon: 5G
AT&T: 5G

Best time to visit California from Ireland

California is a popular destination for Irish holidaymakers. Dublin Airport has regular direct or connecting flights year-round. The best time to visit depends on your preferences for weather, crowds, and value.

Check Device Compatibility Data Usage Calculator

Prices verified: 31 May 2026

Your California eSIM Questions Answered

eSIMs California plans from HelloRoam start from €2.46 and cover LA, San Francisco, San Diego, and the full state on US networks. HelloRoam delivers a QR code by email, activated at home before you board. No roaming charges from your Irish provider, no physical SIM card, and a 180-day refund guarantee on every order.

A HelloRoam e-sim California plan covers the full state from LA to San Francisco on US networks from €2.46, including Big Sur, Napa, and San Diego. Activate at home before your Dublin flight so data is live at LAX or SFO on arrival. No physical SIM, no roaming fees, and a 180-day refund guarantee on every prepaid order.

HelloRoam is a top-rated eSIM for travellers from Ireland visiting California. Plans start from €2.46 and connect to 200+ carrier networks in California at local 4G LTE and 5G speeds. Activate via QR code in under two minutes, keep your Three Ireland, Vodafone IE, or Eir number on dual SIM, and enjoy a full refund window of up to six months. No daily roaming charge and no carrier contract.

A California eSIM starts from €2.46. Fixed data plans run from 1GB to 20GB. Unlimited daily plans suit longer trips. All plans include local 4G LTE and 5G access with no overage charges and no carrier contract. That is far less than what Eir charges for non-EU Worldwide Roaming or Vodafone IE for Global Roaming.

eSIM in California connects to local 4G LTE and 5G networks. Your phone picks the strongest available signal automatically on arrival — no manual carrier selection needed. Coverage spans major cities, airports, main roads, and most rural areas. You get the same local network speeds as residents of California, not the premium daily rates Eir or Vodafone IE charge for international roaming.

Getting your eSIM for California takes three steps. First, choose your plan at helloroam.com and pay in EUR. Second, scan the QR code from your confirmation email in Settings under Mobile Data, then Add eSIM. Third, your e-sim installs in under two minutes and activates when you land. Do everything at home before you head to Dublin Airport, Shannon, Cork, or Knock. No shop visit, no physical SIM swap, no queue.

Yes. iPhone XS and all newer models support your eSIM for California. Go to Settings, tap Mobile Data, then Add eSIM, and scan the QR code from your HelloRoam email. Your Irish number stays active on your main SIM through dual SIM while HelloRoam handles all travel data on the eSIM line. iPhone 14 and later are eSIM-only with no SIM tray needed.

HelloRoam is a solid eSIM choice for California, connecting on T-Mobile and AT&T 5G. Buy your plan before your flight from Dublin Airport, scan the QR code at home, and land at Los Angeles International Airport or San Francisco International Airport already connected. Plans start at $2.87.

HelloRoam eSIM plans work in California on T-Mobile and AT&T 5G. Activate at home before your flight from Dublin by scanning the QR code in your phone settings. Enable data roaming when you land and you'll be online within seconds of arrival.

Your Irish carrier's international roaming charges apply outside the EU. A HelloRoam eSIM costs far less than daily roaming add-ons from Eir, Three Ireland, or Vodafone Ireland. A HelloRoam eSIM from $2.87 gives you local 5G data without daily add-on charges or trips to an airport SIM shop. Sort everything from Dublin before you fly.

HelloRoam eSIM for California connects on T-Mobile and AT&T. Your phone picks the strongest available 5G signal as you travel around California. Coverage is reliable in all main tourist areas and near Los Angeles International Airport or San Francisco International Airport. No manual network selection is needed.

HelloRoam eSIM plans for California start at $2.87. Larger plans with more data and longer validity are available for bigger trips or heavy data users. All plans include 5G data and there are no daily fees or surprise charges. Compare plans at helloroam.com.

A week in California using maps, messaging, social media, and light browsing typically uses 3 to 6 GB. Streaming video in the evenings or video-calling home to Ireland adds more. A 10 GB plan gives you a comfortable buffer for a busy week. HelloRoam offers plans in multiple sizes.

HelloRoam eSIM plans for California run from 12 to 30 days depending on your data size. Pick the plan that covers your full stay from Dublin to your return flight. Scan the QR code before you fly and connect from the moment you land at Los Angeles International Airport or San Francisco International Airport.

California has 5G coverage through T-Mobile and AT&T. HelloRoam eSIM plans connect on the best available signal automatically. Buy your plan before your flight from Dublin Airport and connect on landing at Los Angeles International Airport or San Francisco International Airport without any manual setup.

Number of days	Price
1 day	€2.87
3 days	€8.26
7 days	€19.28
15 days	€39.96
22 days	€55.97
30 days	€73.63

Category	Recommended	Local California SIM card	Eir, Three Ireland, Vodafone Ireland, or GoMo roaming
Typical cost	From €2.46 total	€4.29–€21.44 total	€4.29–€12.87/day
Details	Plans from $2.87. Buy before your flight from Dublin Airport, activate at home over Wi-Fi, and arrive at Los Angeles International Airport or San Francisco International Airport already on local 5G data. No store visit, no ID check, and no wasted time after a long flight.	Available at Los Angeles International Airport or San Francisco International Airport but requires setup time after your flight. Tourist SIMs may need passport registration and in-store activation. Unused data is usually forfeited when your trip ends.	Irish carrier international roaming outside the EU can cost €5 to €15 per day. A week in California on roaming could add €35 to €105 in data charges alone. HelloRoam eSIM starts at $2.87 for your whole trip.

Number of days	Price
1 day	€2.87
3 days	€8.26
7 days	€19.28
15 days	€39.96
22 days	€55.97
30 days	€73.63

Category	Recommended	Local California SIM card	Eir, Three Ireland, Vodafone Ireland, or GoMo roaming
Typical cost	From €2.46 total	€4.29–€21.44 total	€4.29–€12.87/day
Details	Plans from $2.87. Buy before your flight from Dublin Airport, activate at home over Wi-Fi, and arrive at Los Angeles International Airport or San Francisco International Airport already on local 5G data. No store visit, no ID check, and no wasted time after a long flight.	Available at Los Angeles International Airport or San Francisco International Airport but requires setup time after your flight. Tourist SIMs may need passport registration and in-store activation. Unused data is usually forfeited when your trip ends.	Irish carrier international roaming outside the EU can cost €5 to €15 per day. A week in California on roaming could add €35 to €105 in data charges alone. HelloRoam eSIM starts at $2.87 for your whole trip.