What is international roaming, and how does it work?

What is international roaming? 

International roaming is a service provided by mobile carriers that lets you make voice calls, send messages, and use data services when you’re outside your home country. Instead of connecting to your home network, your mobile phone "roams" onto a local network that has a partnership with your service provider, providing seamless connectivity across borders.

In simpler terms, your carrier "borrows" access from a foreign mobile network operator so you can still use your mobile number and services when traveling abroad. 

How does international roaming work? 

International roaming works through agreements between your home mobile carrier and other networks in foreign countries. These roaming agreements let you access mobile services (like making calls, texting, or using data) on the foreign carrier’s infrastructure.

This is how the whole process looks:

• Mobile device detection and network selection. The moment you turn on your mobile phone in a foreign country, it automatically searches for available networks and connects to one that partners with your carrier.

• Authentication. That foreign network checks your SIM details with your home carrier to confirm you're allowed to roam.

• Service access. Once approved, you can use your mobile device as usual. That includes phone calls, text messages, and internet usage. Every action you take is tracked by the local network and reported back to your home carrier.

• Billing. The foreign network bills your carrier, and your carrier bills you, usually with a markup.

The process happens in seconds, so you barely notice it’s happening. What you’ll definitely notice is the price if you’re not careful, especially with data roaming. Apps updating in the background or maps loading on the go will quietly rack up charges before you realize it.

Advantages of international roaming 

People keep using international roaming because it’s easy. The moment you arrive, your mobile phone works, and this seamless connectivity lets you stay connected without interruption. Other benefits include:

• You can keep your existing phone number.

• No SIM swap or extra setup is required.

• You can make and receive calls, send texts, and use apps the same way as at home.

• It’s great for short international trips or emergencies.

• International roaming for business is critical for professionals who need to stay reachable.

In short, roaming makes sense for short-term travel, frequent flyers, or anyone who values convenience over hunting for alternatives.

Disadvantages of international roaming 

International roaming keeps you connected, but it often comes at a price that isn't worth it. The main drawbacks are:

• It’s expensive (especially for data roaming).

• Charges are hard to predict and track.

• Not all destinations are covered.

• It may be slower compared to local SIM cards or embedded SIM (eSIM).

Because you're essentially renting access to another carrier’s network, the roaming rates are usually high — sometimes absurdly so. Plus, many plans come with speed caps, data usage limits, or coverage gaps. That's why many travelers opt for local SIM cards or eSIM services instead.

How much does international roaming cost? 

International roaming services are rarely cheap, and the pricing structure depends on your service provider, your plan, and the country you’re visiting.

• Data roaming: US$5-15 per day.

• Calls: US$0.25-3.00 per minute.

• Text messages: US$0.10-0.50 each.

• Roaming packs: US$10-100 for a set amount of data/minutes.

Let’s explore further by service provider:

* Pricing and features as of September 2025. Always check with your provider for the most up-to-date roaming rates before traveling abroad.

Google Fi and T-Mobile offer the most seamless international data roaming services with minimal extra costs. But if you’re with Verizon or AT&T, you'll likely need to pay US$12 per day unless you use an alternative like an eSIM.

If you're a US resident traveling abroad, costs can be steep, but the same applies in reverse. For visitors, roaming in the USA is often among the most expensive of all destinations, especially if your home carrier doesn’t have strong partnerships with US networks.

How to use international roaming

Using international roaming on your mobile phone usually requires two things:

1. Making sure your plan includes international roaming.

2. Turning roaming on in your mobile phone settings.

You may also need to provision the service. That’s carrier lingo for activating international roaming on your account. You can often do it via your service provider’s app or website. Also, keep in mind that mobile networks vary by country, and in some places your phone may not be compatible with the local system, so check ahead.

Should data roaming be on or off? Leave it roaming off unless you're actively using it. If it’s on and you start using data roaming, it could lead to automatic charges. Turn it on only when you’re ready and make sure you have a roaming pack or a clear understanding of the fees.

Enable international roaming on an iPhone 

For iPhone users, turning on roaming only takes a few taps:

1. Open "Settings."

2. Tap "Cellular" or "Mobile data."

3. Tap "Cellular/Mobile data options."

4. Toggle "Data roaming" to "On."

5. If available, tap "Roaming" to check voice/data settings.

Enable international roaming on Android 

On Android devices, the path may vary depending on the brand, but the process is similar:

1. Open "Settings."

2. Tap "Connections" or "Network & internet."

3. Tap "Mobile network" or "SIMs & network."

4. Toggle "Data roaming" to "On."

A roaming icon appears in the status bar of your Android phone whenever it’s connected to a network outside your carrier’s coverage.

How to avoid high international roaming charges  

If you do plan to use international roaming services, these practical strategies will help you reduce costs and prevent unexpected charges on your next bill:

• Check rates in advance. Know your service provider’s roaming fees and coverage before you leave.

• Buy a roaming package. Activating a bundle ahead of international travel is usually cheaper than paying pay-as-you-go rates.

• Track your data usage. Be aware of what uses data on a cell phone and use a data usage calculator to estimate what you’ll need.

• Limit background activity. Turn off auto-updates and background refresh so apps don't burn data without you noticing.

• Disable data roaming when idle. Only turn it on when you can’t find a Wi-Fi hotspot.

• Be wise about free Wi-Fi hotspots. Do use free Wi-Fi for internet access to save data, but stick to secure connections for banking or sensitive logins.

• Set data roaming limits. Many providers let you set usage limits — use them.

• Skip hotspot sharing. Tethering usually isn’t included in roaming packs.

• Use VoIP services. Apps like WhatsApp, Telegram, or Messenger let you call and text without using mobile data.

A smart way to prepare is to include roaming options in your international travel checklist. That way, you won’t arrive in a new country only to realize you forgot to activate a roaming package, set data alerts, or explore cheaper alternatives.

Still, the best way to dodge additional fees completely is to skip roaming altogether. Solutions like eSIMs, local SIM cards, or international SIM cards offer far more value and help control expenses.

Saily eSIM app: The best way to avoid international roaming charges 

Sick of unexpected charges and sluggish speeds when traveling? The Saily eSIM app gives you fast, affordable mobile data without the roaming headaches.

The benefits of an eSIM are clear:

• Instantly connect to local networks in 200+ different destinations.

• Skip the physical SIM swap because everything’s digital.

• Avoid high roaming rates from your carrier.

• Choose flexible data plans tailored to your trip.

• Activate your plan before you even arrive. Just download the eSIM app and get connected in minutes.

Roaming used to be your only option to stay connected abroad. With Saily, you can use your phone overseas without roaming charges and enjoy freedom, flexibility, and peace of mind when traveling.

If you need even more coverage and high-speed data, Saily Ultra is the premium plan designed for frequent travelers who never want to worry about limits.