eSIM vs. Carrier Roaming: The Cheapest Way to Stay Connected Abroad

For years, travelers had two bad options when landing in a foreign country. You could either hunt for a local SIM card vendor at the airport with jet lag and a language barrier, or you could pay your home carrier an exorbitant fee for the privilege of using your own phone.

The landscape of travel connectivity has changed completely with the adoption of eSIM technology. If you are still paying $10 a day to Verizon or AT&T, you are overpaying by hundreds of dollars per trip. By switching to digital providers like Airalo or Holafly, you can secure reliable data for a fraction of the cost.

The High Cost of Carrier Roaming

Before looking at the solution, it helps to understand exactly how much traditional carriers charge for convenience. The “International Day Pass” model is standard across major US providers, and the costs add up fast.

  • AT&T International Day Pass: This costs $10 per day per line. If you are on a 10-day trip to Italy, that is an extra $100 added to your monthly bill. If you travel with a spouse or child, that cost doubles or triples.
  • Verizon TravelPass: Similar to AT&T, Verizon charges $10 per day to use your domestic plan abroad.
  • T-Mobile: T-Mobile offers a slightly different structure. While plans like Go5G Plus include 5GB of high-speed data in 215+ countries, older or cheaper plans (like Essentials) limit you to 256kbps speeds. That speed is too slow for loading Google Maps quickly or posting Instagram stories.

If you are traveling for two weeks, carrier roaming can easily cost you $140. An eSIM covering the same period might cost you $20 or less.

What Is an eSIM?

An eSIM (embedded SIM) is a digital SIM card that is already built into your phone hardware. You do not need to insert a physical plastic chip. Instead, you download a data plan via an app, install it instantly, and connect to local networks as soon as you land.

Most modern smartphones support eSIM technology. If you have one of the following devices, you are likely ready to go:

  • iPhone: iPhone XS, XR, and all newer models (including iPhone 11, 12, 13, 14, 15 series).
  • Samsung: Galaxy S20 and newer.
  • Google: Pixel 3 and newer.

Airalo: Best for Budget and Moderate Data Users

Airalo is the most popular marketplace for eSIMs. They act as a broker, reselling data from local networks (like Movistar in Spain or Orange in France) at wholesale rates.

How Pricing Works

Airalo generally operates on a capped data model. You buy a specific amount of data valid for a set number of days. This is perfect for travelers who mostly use Wi-Fi at hotels but need data for maps and WhatsApp while walking around.

Real-world pricing examples (as of 2024):

  • Europe (Regional Plan): A “Eurolink” eSIM covering 39 countries costs roughly $13 for 3GB (30 days) or $37 for 10GB (30 days).
  • Japan: 3GB for $8.50.
  • USA (for incoming tourists): 5GB for $16.

Compared to the $140 you might pay Verizon for a two-week trip, paying $13 to Airalo for 3GB of data represents over 90% savings.

Pros:

  • Extremely cheap for short trips.
  • Top-tier app that makes installation easy.
  • Regional plans allow you to cross borders without changing settings.

Cons:

  • Data is not unlimited. If you stream Netflix on 5G, you will run out.
  • Does not usually include a phone number for voice calls (data only).

Holafly: Best for Heavy Data Users

If you do not want to worry about monitoring your data usage, Holafly is the better alternative. Their primary selling point is unlimited data.

How Pricing Works

Holafly charges based on the number of days you are traveling rather than the gigabytes you consume.

Real-world pricing examples:

  • Europe (Unlimited Data): 5 days for $19, 10 days for $34, or 20 days for $54.
  • Asia (Unlimited Data): 10 days for roughly $37.

If you are a content creator uploading 4K video or a business traveler constantly on Zoom calls without Wi-Fi, Holafly offers peace of mind. You pay a flat rate and never hit a cap.

Pros:

  • Truly unlimited data in most regions.
  • Connects to multiple carriers in one country for better coverage.
  • 24⁄7 customer support is generally very responsive.

Cons:

  • More expensive than Airalo for light users.
  • Tethering restrictions: Historically, Holafly did not allow hotspot usage (sharing data to your laptop). They have recently started allowing limited tethering on some plans, but you must check the fine print for your specific destination.

How to Set Up Your eSIM (Step-by-Step)

The process can seem intimidating if you have never done it, but it takes less than five minutes.

  1. Buy Before You Fly: Download the Airalo or Holafly app and purchase your plan while you are still at home on your own Wi-Fi.
  2. Install the eSIM: The app will guide you. Usually, you just click “Direct Install” or “Activate.” Your phone will guide you through a setup screen.
    • Label your new line “Travel” or the name of the country.
    • Label your main line “Home.”
  3. Configure Settings:
    • Go to Settings > Cellular (or Mobile Data).
    • Set Cellular Data to use the “Travel” eSIM.
    • Turn Data Roaming ON for the “Travel” eSIM.
    • Turn Data Roaming OFF for your “Home” line to avoid accidental charges from Verizon/AT&T.

Keep Your Number for Two-Factor Authentication

One major advantage of using an eSIM alongside your physical SIM is that you can keep your home line active for texts.

By leaving your “Home” line on but disabling data roaming, you can usually still receive incoming SMS texts (which is free on many carriers). This is critical for receiving Two-Factor Authentication (2FA) codes for banking apps or email. Just ensure you do not answer phone calls or send outgoing texts, as those will trigger roaming fees.

Frequently Asked Questions

Will my WhatsApp number change? No. When you switch to an eSIM for data, WhatsApp will ask if you want to keep your existing number. Select “Keep” and all your chats and contacts will remain exactly the same.

Can I make regular phone calls with an eSIM? Most travel eSIMs from Airalo and Holafly are data-only. This means you cannot use the standard phone dialer to call a restaurant. However, you can make calls using VoIP apps like WhatsApp, FaceTime Audio, Skype, or Google Voice.

Does my phone need to be unlocked? Yes. This is the most important requirement. If you are still financing your phone through AT&T or Verizon, it might be “carrier locked,” meaning it cannot accept an eSIM from another provider. You must call your carrier to request an unlock before you travel.

Is 5G available on these eSIMs? It depends on the specific country and package. Airalo and Holafly clearly label their plans as “4G/LTE” or “5G.” In major hubs like London, Tokyo, or New York, 5G is standard. In rural areas or developing nations, you will likely connect to 4G networks.