Does an Erasmus student need an eSIM?
The short answer is yes, and the main reason is the duration of the stay. A weekend trip can be managed with your Spanish operator's roaming. But an Erasmus stay lasts between 3 and 12 months, and during that time you need internet for online classes, finding accommodation, getting around the city, keeping in touch with family and friends, and working on academic documents in the cloud.
Roaming within the EU has been free since 2017 under the "Roam Like at Home" policy. In theory, you can use your Spanish plan in any European Union country. In practice, most operators apply a fair use limit that reduces speed or data volume after a certain number of days outside of Spain. With a long stay like Erasmus, this limit will inevitably be triggered.
Furthermore, many prepaid contracts or low-cost plans do not include unlimited EU roaming. Check the fine print of your contract before assuming you have free coverage all year round.
A specific European eSIM gives you a dedicated data line, with coverage in most Erasmus+ program countries, no surprises on your bill, and no reliance on your Spanish operator's fair use limits.
How much data do you need for Erasmus?
This is one of the most frequently asked questions among students going on Erasmus. The answer depends on your digital lifestyle, but we can give you a realistic estimate:
- Online classes and video conferences (Zoom, Teams, Google Meet): 600 MB – 1.5 GB per hour of class.
- Social media (Instagram, TikTok, YouTube): 1-3 GB per day if you regularly consume video.
- Maps and navigation (Google Maps, Citymapper): 200-400 MB per month if you don't use them offline.
- Messaging (WhatsApp, Telegram): less than 200 MB per month unless you send videos continuously.
- Cloud work (Drive, OneDrive, Notion): 300-800 MB per month.
Adding up moderate use, an Erasmus student consumes between 10 and 25 GB per month. If you watch a lot of streaming video or make many video calls from your mobile (not from WiFi), you can exceed 30 GB.
Our recommendation: choose a plan of at least 15 GB per month if you use campus WiFi a lot, or 25-30 GB if you mainly rely on mobile data. Many eSIMs allow you to top up data at any time, which provides flexibility if you use more than usual one month.
For a more detailed guide on data consumption, check out our article how much data do I need for travel.
eSIM vs. local SIM card in the Erasmus country
Many students consider the alternative of buying a local SIM in their destination country. It's a valid option, but it has more friction than it seems at first glance.
Local SIM: advantages and disadvantages
- It's usually cheaper in countries like Germany (Aldi Talk, Lidl Connect) or France (Free Mobile, SFR).
- You get a local number, which can facilitate procedures like opening a bank account or renting an apartment.
- But you temporarily lose your Spanish number (unless you use dual SIM).
- If you travel to other countries during Erasmus—and all Erasmus students travel—roaming with that local SIM can be expensive outside the EU.
- It requires comparing plans in a language you may not yet be proficient in.
Europe eSIM: advantages and disadvantages
- It activates before leaving Spain, without needing to manage anything in the destination country.
- Coverage in most European countries on a single plan.
- You can keep your Spanish number active on a second line (dual SIM).
- The price is usually competitive for stays of 1-3 months; for longer stays, a local SIM might be more economical.
The ideal solution for a long Erasmus stay (6-12 months) is to use both options in parallel thanks to dual SIM: a data eSIM to maintain coverage in any European country, and a physical local SIM to have a number from the destination country. Learn how dual SIM works in our guide eSIM dual SIM: how it works.
Quick comparison: three ways to get data during Erasmus
Before deciding, it's worth looking at the three options side-by-side. None is perfect for all cases: it depends on how many countries you plan to visit during the course and how long your scholarship lasts.
| Criteria | Roaming with Spanish plan | Local physical SIM | Europe eSIM |
|---|---|---|---|
| Activation | Automatic, no management required | In-person procedure at a store or kiosk | Online, before travel |
| Your Spanish number | Maintained | Lost unless physical dual SIM | Maintained if mobile supports dual SIM |
| Coverage if traveling to multiple countries | Covered within the EU | Limited to purchase country, expensive roaming outside | Covered in most European countries with a single plan |
| Risk with long stays | Disconnection or limitation due to fair use | None once activated | None if you renew the monthly cycle |
| Process language | Spanish | That of the destination country | Spanish |
| Recommended for | Short stays or one week | Very long Erasmus in a single country with university agreement | Erasmus of 3-12 months with mobility between countries |
The best eSIM options for long stays
Not all eSIMs are designed for stays of several months. Tourist eSIMs typically have a validity of 7 to 30 days. For an Erasmus stay, you need plans with longer validity or the option to renew monthly.
Features a good Erasmus eSIM should have:
- Validity of 30 days or more, renewable without interruptions.
- Coverage throughout Europe, especially in the main destination country.
- Sufficient data: minimum 15 GB/month, ideally 25-30 GB.
- No contract commitment: flexibility to cancel when you return to Spain.
- Spanish support in case of technical problems.
At PuraSim, we offer European eSIM plans specifically selected for long stays, with coverage in over 30 European countries. Check all options in our European eSIM collection.
To compare plans, pay special attention to the cost per GB and the guaranteed maximum speed. Some economical plans limit speed to 3G or reduced speed, which may be insufficient for high-quality video calls.
Keeping your Spanish number abroad
This is one of the biggest concerns for Erasmus students. Your Spanish phone number is linked to your bank's authentication, WhatsApp, many Spanish university apps, and your contact network. Losing it or letting it become inactive for months can create problems.
Options for keeping your Spanish number active during Erasmus:
- Keep your Spanish SIM card in your mobile: If your smartphone is dual SIM, you can have the Spanish SIM in one slot and the data eSIM on the virtual line. You will receive calls and SMS on your Spanish number without consuming Spanish data.
- Port to a low-cost plan: Some operators like Lebara, Lowi, or Simyo offer very cheap line-only plans (no data), perfect for keeping your number active while using the eSIM for data.
- Call forwarding: Set up call forwarding from your Spanish number to a VoIP number like Google Voice or a WhatsApp Business number, so you don't miss important calls.
Most modern smartphones (iPhone XS onwards, Samsung Galaxy S20 onwards, and many mid-range Android phones from 2021) support dual SIM with eSIM. This means you can have your Spanish line and your data eSIM active simultaneously without needing to swap physical cards.
For more information on managing connectivity abroad, visit our page eSIM for travel.
What almost no one tells you about eSIMs for Erasmus
There are several details you only discover when you're already caught up with enrollment, housing, and your first exam. We'll tell you about them in advance so they don't catch you off guard halfway through the course.
The "roam like at home" has a hidden catch. It's not just about a limit of a few days: European regulations include a stable link and predominant consumption criterion that reviews, over several months, which country you actually use your line in. If your operator detects that you've been connected almost always outside of Spain for half a year, they can apply surcharges even if you haven't exceeded any specific GB limit that month. To understand how data roaming truly works—and why "free" doesn't mean "without conditions"—take a look at our guide on what data roaming is before assuming that roaming will cover you for twelve months without further ado.
Residency procedures sometimes require a local number. In some countries, the appointment for a residency permit or municipal registration sends the confirmation SMS only to numbers on that local network; a Spanish number with a data eSIM won't work for this. If your Erasmus includes registration or a residency permit, first find out if the procedure requires a local number before completely ruling out a physical SIM.
Banking apps can lock you out if you deactivate your Spanish line. Two-factor authentication for most Spanish banks sends the SMS code to the number you have registered, not the one you use for browsing. If you completely replace your Spanish SIM instead of combining it with a dual SIM, you run the risk of being locked out of your own account in the middle of an urgent payment. This is another strong reason to keep your Spanish line active while using the eSIM only for data.
When NOT to buy a Europe eSIM: if your host university has an agreement with a local operator for students—common in Germany and the Netherlands, where some faculties offer enrollment plans with mobile lines included or heavily discounted—that option is usually more cost-effective after the second or third month than any eSIM. In that case, it makes sense to use the eSIM only for the first week, while you process the local SIM, and cancel it as soon as you have the definitive country line.
Buy the eSIM before orientation week, not on the first day. The eduroam at your host university almost never works on the first try: you have to register your credentials, wait for them to propagate across campuses, and, in many cases, go through IT support. That first week—the one where you're queuing at the immigration office, looking for an apartment, and finding the nearest supermarket—is exactly when you most need reliable data and have the least room to resolve an activation issue. And if you're going to use apps with SMS or WhatsApp verification as soon as you land, it's worth knowing how to protect that connection on airport public WiFi or shared apartment WiFi: we explain it in our guide to privacy and VPN while traveling.
One last practical detail: if your phone is a mid-range model purchased more than four years ago, check before paying anything that it is eSIM compatible, because not all Android phones are, even if the model sounds recent. The installation process is simple, but it should be done calmly and with stable WiFi—don't leave it until the airport. We explain it step-by-step in how to install an eSIM.
Conclusion
An eSIM is the most practical solution for the modern Erasmus student. It allows you to activate connectivity before leaving Spain, cover all European countries without local hassle, and keep your Spanish number active in parallel.
The monthly cost of a European eSIM is significantly lower than what you would pay for free roaming with a standard Spanish operator after exceeding the fair use limit. And it's much more convenient than looking for local SIMs in every country you visit during your Erasmus.
Our plans are specifically designed for long stays in Europe. Check out the available options and start your Erasmus connected from day one.
Frequently asked questions about eSIM for Erasmus
Can I use my Spanish plan on Erasmus without additional cost?
Within the EU, you have free roaming under the Roam Like at Home policy, but with a fair use limit. For long stays like Erasmus, many operators apply restrictions after a certain number of days or GB consumed outside of Spain.
How many GB per month do I need as an Erasmus student?
Moderate use (online classes, social media, browsing) consumes between 10 and 25 GB per month. If you watch a lot of streaming or make many video calls using mobile data, you can exceed 30 GB.
Can I keep my Spanish number during Erasmus?
Yes. With a dual SIM mobile, you can have your physical Spanish SIM in one slot and the data eSIM on the virtual line. This way, you receive calls and SMS on your Spanish number while using the eSIM for browsing.
Does the eSIM work in all Erasmus+ program countries?
European coverage eSIMs generally cover more than 30 countries, including all EU countries and several other Erasmus+ program countries such as Norway, Iceland, or Turkey. Verify the list of covered countries before purchasing.
Is it better to buy a local SIM or an eSIM for Erasmus?
It depends on the duration and your needs. For short stays or if you travel to several countries, the European eSIM is more practical. For very long stays in a single country, a local SIM may be more economical. The ideal combination is a data eSIM + a local SIM to have a number from the destination country.
What happens if my Europe eSIM runs out of data before the end of the month?
Most plans allow you to top up additional data without waiting for the monthly renewal, or to purchase an occasional extra package. Check your specific plan's top-up option before running out of connection mid-month.
Do I need a different eSIM for each country if my Erasmus includes several destinations?
No, if you choose a European coverage plan that includes several countries in the same plan, you don't need to buy a new eSIM every time you cross a border within that coverage area. It would only make sense to consider an additional plan if you leave the area covered by your current plan.
