What is international roaming and how does it work?
International roaming is the service that allows your cell phone to continue making and receiving calls, messages, and using mobile data outside your home country, connecting to a local operator's network through a commercial agreement between both companies. Your number doesn't change, but the cost of the service almost always does.
When you cross a border with your cell phone turned on, the device automatically searches for an available network in that country. If your home operator has a roaming agreement with one of the local networks, your cell phone connects to it and continues to function as if you were at home, even though you are technically using another company's infrastructure. This agreement between operators is precisely what makes it possible for you to call, send messages, or browse without having to buy a new line in each country you visit.
What is almost never clear to travelers is that this service is neither free nor automatically included in their local plan: it usually triggers an additional charge, either per usage (megabytes, minutes, messages) or for a specific roaming package that you have to contract before or during your trip.
If your line is from ETB in Colombia, the same principle applies: roaming is not included free in your plan, so it's advisable to check their app or website for available options for your destination before traveling.
How to activate international roaming before a trip?
Before traveling, the first step is to confirm with your own operator whether international roaming is activated by default on your line or if you need to request it. In many countries, for security against accidental charges, it comes deactivated and must be manually enabled from the operator's app, your account website, or by calling customer service. If you use ETB, for example, the place to confirm this is their own app or client portal, as the conditions and available packages by destination are only published and updated by the company.
Once you've confirmed that roaming is enabled on your line, it's a good idea to check three things before getting on the plane:
- If your operator offers any specific package or add-on for the country or region you are visiting, instead of leaving usage open per loose megabyte.
- If you need to activate that package manually from the app, or if it activates automatically when your phone connects to a foreign network.
- How to deactivate data roaming (not necessarily call and SMS roaming) from the phone's own settings, in case you decide to use another connection alternative during the trip.
That last point is key: roaming activation depends not only on the operator, but there is also a switch within the cell phone's operating system (in Settings, within the mobile network section) that controls whether the device can use data outside your country, even if your operator has already enabled it on the network side.
How much can international roaming cost?
The cost of international roaming depends on the operator, the destination, and whether you contract a fixed package or pay per usage. Since this combination changes constantly and varies by country, each operator publishes its current rates on its site or app, so the most reliable way is to check it directly there before traveling, rather than assuming.
What can be anticipated are the factors that cause this cost to go up or down:
| Factor | What to ask your operator | Why it matters |
|---|---|---|
| Destination charging zone | Is the country I'm traveling to in an "economical" zone or the most expensive on their list? | The same operator can charge very different amounts depending on the destination, even between neighboring countries. |
| Loose consumption vs. fixed package | Is the charge per megabyte/minute consumed or for a package with a fixed limit? | Loose consumption charges typically generate the highest and most unpredictable bills. |
| Incoming calls | Are incoming calls also charged for abroad, not just outgoing calls? | It's common in roaming to also be charged for receiving calls, something many travelers don't expect. |
| Social media and streaming | Does the package include or exclude video, music, and social media? | Streaming consumes data quickly and can exhaust an entire package in a few hours. |
| Trip duration | Are there daily packages or only monthly options? | A package designed for a month can be more expensive than a daily one if the trip is short. |
Before traveling, the right question is not "do I have roaming activated?", but "do I know exactly how much each megabyte, each minute, and each message I use there will cost me?". Your operator answers the first question with a yes. The second is only answered by checking the published conditions, with a date, before getting on the plane.
How to make an international call from your cell phone abroad?
To call from abroad, whether to your home country or a local number in the country you are in, you generally need to dial the international exit code (almost always "+" or "00"), followed by the country code of the destination and then the number, without the initial 0 sometimes used for local calls.
For example, if you are traveling and want to call a number in your home country, you would typically dial the "+" symbol followed by that country's code (each country has its own) and then the full number. If, on the other hand, you want to call a local number in the country you are in, in most cases it is enough to dial it as a resident of that place would, without adding any additional code.
Now: that call, although technically possible to dial, can generate a roaming charge if your cell phone is connected to a foreign network with voice roaming activated. That's why more and more travelers choose to make calls over the internet (WhatsApp, video call, messaging apps) instead of through the traditional telephone network, using data instead of voice minutes. That is also one of the reasons why having reliable mobile data during the trip, without depending on voice roaming, has become so relevant.
This applies equally with ETB: the dialing method does not change according to the operator, but what can change is whether you have voice roaming activated and what the company charges you for that call.
Which network does your cell phone use when roaming is activated?
When you activate roaming, your cell phone doesn't continue to use your home operator's network: it connects to a local operator's network in the country you are in, thanks to a prior commercial agreement between both companies. Your home operator acts as an intermediary that bills for that usage, but the physical signal is provided by the visited country's network.
This explains two things that often confuse travelers:
- Why the quality of the signal in roaming can be different from what you have at home: it depends on the network of the local operator with whom your operator has an agreement, not your own.
- Why in some countries the cell phone may show more than one available operator when searching for a network: the system automatically chooses one of those that have a roaming agreement with your home operator, and in some cases, you can manually select the network from the settings if the automatic one has a poor signal.
Which specific local operator provides that signal depends on each company's current agreement in each country, and that information can only be confirmed by your own operator, as it changes over time and is not the same in all destinations. In the case of ETB, the network your cell phone receives abroad also depends on their current agreements in each destination, so if you need to know exactly which one it is, the most reliable answer will come from the company itself, not a generic list.
Automatic roaming vs. roaming plan: what's the difference?
Automatic roaming is what happens when your cell phone automatically connects to a foreign network upon detecting that you have left your country, without you having to do anything, and begins to generate usage (and charges) from that moment if data roaming is enabled on the device. A roaming plan or package, on the other hand, is a specific product that you contract with your operator for that trip, usually with a predefined limit of data, minutes, or days.
The practical difference is control over spending: with automatic roaming without a contracted package, usage can be billed per unit (MB, minute, SMS) without a clear cap, while a contracted package gives you a known limit before you travel. Therefore, if you decide to use your operator's roaming, it is almost always advisable to contract a specific package for the destination instead of leaving it in automatic mode without a limit.
A trick that many cell phones allow and few use: separating the "data roaming" switch from the "calls and SMS roaming" switch. You can keep your line's calls and messages active (to stay in touch and receive SMS verifications) while keeping mobile data roaming off, thus avoiding the part of usage that accumulates fastest.
The most common mistakes that lead to unexpected bills
Most roaming bills that surprise you upon returning from a trip share a common origin: the cell phone was using mobile data in roaming without the person realizing it, generally due to applications that continue to update, synchronize, or download content in the background even if the phone is tucked away in a pocket.
Among the most frequent cases are leaving automatic app updates enabled, photo and video synchronization to the cloud, or music and video streaming without checking beforehand whether such usage is included in the contracted package. It is also common not to verify if incoming calls incur costs, and to be surprised to find that answering a call, not just making one, was also charged.
Another common mistake is assuming that, because you used roaming without issue on a previous trip to another country, the same conditions automatically apply to the next destination. Each country and each roaming agreement is different, so what was economical on one trip may not be on the next if it is not re-checked before leaving.
The eSIM: the alternative few travelers know about
Beyond activating or not activating roaming with your usual operator, there is another way to have mobile data abroad that many travelers still don't know about: the travel eSIM. It's a digital SIM card, integrated into the cell phone, which is installed over the internet instead of being physically inserted, and which you can activate specifically for the country or region you are going to visit, with a known data consumption from before you buy it.
A typical case helps to understand the difference. Imagine you are planning a ten-day trip, with several cities on the agenda, and you need data for maps, to request transportation, and to stay in touch via messaging throughout the journey. With traditional roaming, you would have to confirm with your operator if that destination has an available package, how much it covers, and what happens if you run out of data halfway through the trip. With a travel eSIM, on the other hand, you install the data profile for that destination before leaving (or even once you are there, as soon as you have Wi-Fi), you know from the moment of purchase how much you are going to pay, and you can check your remaining consumption during the trip without surprises upon returning.
A not-so-obvious detail worth knowing: on a dual SIM phone (one physical and one eSIM, which most phones in recent years allow), you can keep your local line active only for calls and verification messages, while all data consumption runs exclusively through the travel eSIM. This way, you keep your usual number available for essential communication, without that side incurring roaming charges, because data—which is what is consumed fastest—goes through a completely different channel.
Before deciding on an eSIM, it's a good idea to confirm that your phone supports it and understand how to install it step by step, which you can calmly review in the guide on what an eSIM is, in the list of compatible phones, and in the step-by-step guide on how to install an eSIM.
Roaming vs. eSIM: comparative table to decide on your next trip
Neither option is incorrect in all cases: the best choice depends on how long you travel, how much you use your phone, and how much you value knowing the cost beforehand. This table summarizes the most practical differences.
| Aspect | Traditional Roaming | Travel eSIM | |
|---|---|---|---|
| Activation | Depends on your operator: may require a call, app, or activate automatically when crossing the border. | Installed from the phone itself, without needing to go to a physical store. | |
| Your local number | Remains active for calls and messages natively. | Can also be kept active if you use the eSIM only for data and keep the physical line for calls. | |
| Destination coverage | Varies according to the agreements your operator has in each country. | In PuraSIM's case, it covers more than 200 destinations with the same product type. | |
| How it's paid | Can be charged per consumption or per package, depending on the operator and destination. | Purchased before the trip, with the amount known from that moment. | |
| Support if something goes wrong | From your local operator, subject to hours and country. | At PuraSIM, available 24/7 in all languages via email and WhatsApp. |
If you want to delve deeper into this comparison with more technical detail, the eSIM vs. roaming guide elaborates on each point separately.
Frequently asked questions
Do I need to call my operator to activate international roaming?
It depends on the operator. Some activate it instantly from their app or website, others ask for a call or a confirmation message. The safest thing is to check a few days before traveling, not on the day of the flight.
Does roaming work the same in all countries?
No. The availability, signal quality, and cost depend on the specific agreement your operator has with local networks in each country, so conditions can change significantly from one destination to another.
Can I use WhatsApp and social media with roaming activated?
Yes, as long as data roaming is enabled and you have available usage. Using social media and messaging apps consumes data like any other app, so it's deducted from your package or charged per usage, depending on your plan.
What happens if my roaming package runs out halfway through the trip?
It depends on the operator: some cut off data service until you buy more, others automatically switch to loose consumption billing, which is usually the most expensive option. It's advisable to confirm this before contracting the package.
Are roaming and eSIM the same?
No. Roaming is a service offered by your own operator for your line to continue working outside the country. A travel eSIM is a different data profile, independent of your home operator, which you install specifically for the destination you are going to.
Do I need a special phone to use a travel eSIM?
You need a cell phone that has the eSIM function, which most mid-range and high-end models from recent years already have. You can confirm if yours is compatible in the list of eSIM compatible phones before purchasing.
Does ETB have international roaming for its mobile lines?
Like most carriers, ETB offers an international roaming service for its lines. The conditions, covered destinations, and available packages change frequently, so the most reliable way to check them is directly on the ETB app or website before each trip, rather than assuming they will be the same as on a previous trip.
Can I use roaming and an eSIM at the same time on the same trip?
Yes, if your phone supports dual SIM. You can keep your local line (with or without voice roaming) for calls and SMS, and use the eSIM exclusively for data, or even switch between them as needed during the trip.
In summary: what's best depending on your type of trip
If you're traveling for a few days and will use your cell phone minimally, checking with your carrier if they have a specific roaming package for that destination, and activating it with a clear limit, might be sufficient. But if your trip lasts several days, you visit more than one country, or you simply prefer to know exactly how much you'll pay before boarding the plane, a travel eSIM solves precisely that uncertainty: you buy it with the destination and consumption defined in advance, activate it in minutes from your phone, and avoid being tied to the changing conditions of a carrier that are not always designed for infrequent travelers.
To take the first step, you can check the international eSIM collection and choose the destination for your next trip, or start with the ultimate guide to eSIM for travel if it's your first time using one. Whichever option you choose, the important thing is to decide before you leave, not after seeing the bill.
