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HelloRoam's California eSIM starts from €2.48 and taps into 199+ carrier networks across 185+ countries. Scan the QR code and you're online in under two minutes, on any eSIM compatible phone. Your Three Ireland, Vodafone IE, or Eir number keeps running on dual SIM.
199+
local networks
5G
5G support
2 minutes
to activate
![California [[networkType]] network speeds](/icons/figma-2026/stats-speedometer.svg){kind=icon}
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California eSIM coverage and activation
Cheap eSIM for California, starting from €2.48. Local 4G/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 €2.48 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 on unactivated eSIMs, GDPR-compliant checkout.
California eSIM with fast 5G coverage
HelloRoam offers eSIM plans for California starting from €2.48. 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 €2.48 with 5G speeds
- Coverage from AT&T and 1+ other operators
- Instant activation in under 2 minutes
- 180-day money-back guarantee
- California coverage across major cities
- Network
- 5G
- Plans From
- €2.48
- Activation
- Under 2 min
- Guarantee
- 180 days
How to Set Up an eSIM in California
Pick a data plan for your destination and complete checkout online.
Scan the QR code to install your eSIM instantly.
Your eSIM installs instantly and activates the moment you land.
Track usage, top up data, and manage all your eSIMs in one place.
Pick a data plan for your destination and complete checkout online.
Scan the QR code to install your eSIM instantly.
Your eSIM installs instantly and activates the moment you land.
Track usage, top up data, and manage all your eSIMs in one place.
Trip changed? No bother, we have got you sorted.
Travel plans shift, and that's grand. HelloRoam refunds unactivated, unscanned eSIMs in full for up to 180 days after purchase, no drama.
Learn more about our refund policyHelloRoam 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 €2.48 with instant QR activation and a 180-day refund on unactivated eSIMs.
| Feature |  | Irish carrier roaming add-on | Limited data eSIM |
|---|---|---|---|
| 180-day refund policy |  |  | |
| 24/7 live chat support | |  | |
| €0 activation fees | | | |
| Free hotspot and data sharing | | | |
| 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 | | Airalo | Holafly | Nomad | Saily | Ubigi |
|---|---|---|---|---|---|---|
| 180-day refund policy | | | | | | |
| 24/7 live chat support | | | | | | |
| €0 activation fees | | | | | | |
| Free hotspot and data sharing | | | | | | |
| No data overage charges | | | | | | |
| Instant QR code delivery | | | | | | |
| Premium California carrier networks | | | | | | |
| Own branded carrier identity (SPN) | | | | | | |
What Is an e SIM? How eSIM Works in California
An eSIM is a digital SIM built directly into your phone: no plastic chip, no SIM tray. Scan a QR code to activate in under 2 minutes on any eSIM compatible iPhone or Android. It works as a prepaid data plan for California travel with no airport SIM counter, no physical SIM card, and no carrier contract. Sort everything at home before you head to Dublin Airport, Shannon, Cork, or Knock and you are ready to go the moment you land. guide
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 €2.48.
- HelloRoam connects to AT&T 5G, Verizon 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 €2.48 and give you instant 5G data on arrival.
- AT&T
- 5G
- Verizon
- 5G
HelloRoam eSIM vs Irish carrier roaming in California
Your connectivity options for a trip to California from Ireland. Compare HelloRoam eSIM plans against buying a local SIM card or using your Irish carrier's roaming add-on.
RecommendedFrom €2.48 total
Plans from €2.48. 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.
€4.32–€21.61 total
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.
€4.32–€12.96/day
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 €2.48 for your whole trip.
| Category | Recommended | Local California SIM card | Eir, Three Ireland, Vodafone Ireland, or GoMo roaming |
|---|---|---|---|
| Typical cost | From €2.48 total | €4.32–€21.61 total | €4.32–€12.96/day |
| Details | Plans from €2.48. 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 €2.48 for your whole trip. |
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.
Top Attractions in California
Big Sur
Big Sur is a rugged stretch of California coast with cliffs, redwoods, and the Pacific. Use HelloRoam eSIM to stay connected.
Pull over at McWay Falls viewpoint for a waterfall dropping onto the beach.
California Street
California Street in San Francisco climbs Nob Hill with cable car tracks and city views. Use HelloRoam eSIM to stay connected.
Ride the California Street cable car for a steep climb with bay views.
Malibu Beach
Malibu Beach stretches along the Pacific Coast Highway with surf breaks and celebrity homes. Use HelloRoam eSIM to stay connected.
Try El Matador Beach for dramatic rock formations and fewer crowds.
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Your California eSIM Questions Answered
eSIMs California plans from HelloRoam start from €2.48 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 unactivated eSIMs on every order.
A HelloRoam e-sim California plan covers the full state from LA to San Francisco on US networks from €2.48, 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 unactivated eSIMs on every prepaid order.
HelloRoam is a top-rated eSIM for travellers from Ireland visiting California. Plans start from €2.48 and connect through our worldwide network of 199+ carriers, giving you local 4G/5G speeds in California. Activate via QR code in under two minutes, keep your Three Ireland, Vodafone IE, or Eir number on dual SIM, and enjoy a 180-day refund window on unactivated eSIMs. No daily roaming charge and no carrier contract.
A California eSIM starts from €2.48. Fixed data plans run from 1GB to 20GB. Unlimited daily plans suit longer trips. All plans include local 4G/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/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 €2.48.
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 €2.48 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 €2.48. 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.
