1 · The 60-second answer

Studying abroad for a semester or a full year is a different problem from a two-week holiday. I read it as one question, and it is not "where do I get data." It is "how do I stay reachable on the number my bank, my university, and my family already have, without paying roaming rates for months on end."

I compared three real options. You can roam on your home plan, which keeps your number but stacks up a bill over a long stay. You can buy a local SIM in your host country, which is cheap local data but a brand-new number that breaks your two-factor logins. Or you can use a global eSIM that travels with you.

Ringo is a monthly eSIM subscription that runs across 180+ countries, includes calls and SMS, and ports your existing number so the same digits work the day you land and every day after. For most students moving abroad, I think keeping the number matters more than they expect.

2 · What a student actually needs (it isn't just data)

Travel guides obsess over gigabytes. For a few days in one city, that is the whole story. For a semester it is not. This is what I look for when someone lives somewhere new:

  • Data that lasts the whole stay. Maps on day one, lecture recordings, video calls home, and no need to re-buy a plan every 30 days.
  • A number that receives your 2FA codes. Your home bank, your university portal and your government student-finance login all text codes to the number they have on file.
  • Calls and texts that work both ways. You want a local number for a flat viewing or a part-time job, and your family back home reaching you on the number they already know.
  • It works on the phone you own. That means no second handset and no shop queue in a language you are still learning.

A data-only travel eSIM covers the first point and ignores the rest. I think that gap is where students get caught.

3 · Roaming vs local SIM vs a global eSIM

Here is my side-by-side for someone living abroad for months, not days:

Swipe to compare →

What you needRoam on home planLocal SIM abroadRingo
Keep your existing numberYesNo, a new local numberYes, your number ports
2FA to home bank and uniWorksBreaks (codes go to old number)Works
Calls and SMSYes, at roaming ratesLocal onlyYes, included
Cost over a full yearAdds up fastLow locallyFlat monthly
Reachable the day you landYesAfter a shop visit and IDYes, scan a QR
Weekend trips to nearby countriesExpensiveNew SIM each country180+ countries on one plan

A local SIM is genuinely cheap for in-country data, and I will give it that. The catch is the new number. Every login tied to your old digits stops working, and you will be juggling two numbers for the rest of the year.

4 · Keeping your home number is the part students underestimate

The first week abroad is admin week. You open a local bank account, register your address, enrol on the university system and sort student finance. Almost every one of those steps sends a verification code by SMS, and it sends it to the number on your account, which is your home number.

If you have swapped to a local SIM, those codes land on a number you can no longer use. People end up borrowing a friend's phone back home to read a bank code, or waiting days for a workaround. I would keep the number, so the codes just arrive, wherever you are.

There is a softer reason too. Your parents, your friends and your old job all have one number for you, and porting it onto a global plan means nothing changes for them. For the full mechanics, I would read .

5 · The day you land · a setup checklist

I want you to step off the plane already connected, not hunting for a shop or airport Wi-Fi. An eSIM lets you set everything up before you fly.

Before you fly (on home Wi-Fi):

  • Check that your phone supports eSIM (iPhone XS and later, Pixel 3 and later, Samsung S20 and later) and is not network-locked.
  • Sign up and start your number port a few days early, so the switch happens while you are still home.
  • Install and activate the eSIM. It is three taps in Settings, and the shows each one.

When you land:

  • Turn off airplane mode, and your line connects to a local network automatically.
  • Send a quick message home so everyone knows you arrived.
  • Open maps and get to your accommodation, with no queue, no kiosk and no roaming surprise.

After that, admin week runs on the number you already had, codes and all.

6 · How to choose the right setup for your stay

I would match the option to the shape of your stay, not to the marketing:

  • A short exchange (a few weeks) in one country. A data-only travel eSIM is often enough, especially if you do not need your home number for logins. I would read for the trade-offs.
  • A full semester or year. You will do bank and university admin on your home number, so I would keep it (Ringo, or roaming if you can stomach the bill) over a local SIM.
  • Studying somewhere you'll travel from often. Erasmus students hopping borders most weekends pay again and again with local SIMs. One plan that spans 180+ countries removes that.
  • On a tight budget for one country only, and willing to change your number. A local prepaid SIM is the cheapest pure-data route, and it wins that row. Just know what you give up.

7 · Frequently asked questions

Can I set up my eSIM before I fly out to university?+
Yes, and I would. An eSIM installs over Wi-Fi, so you can activate it at home before departure. If you keep your number, start the port a few days early so the switch lands while you are still on home Wi-Fi. Your line is then live the moment you land.
Does my phone need to be unlocked?+
For most eSIM setups, yes. A network-locked phone can refuse to load another carrier profile. If you bought your phone on a contract, I would ask your carrier to unlock it before you travel. It is usually free once the contract conditions are met.
Will my home bank and university 2FA codes still reach me?+
If you keep your existing number, yes. Codes go to the number on your account, so porting that number onto a global plan means they arrive wherever you are. If you switch to a new local SIM, those codes go to a number you can no longer read. I count that as the most common problem students hit.
eSIM or local SIM for a one-semester exchange?+
It depends on whether you need your home number. If you will do banking, student finance or university logins that text your existing number, I would keep it. If you only need cheap in-country data and do not mind a new number, a local SIM is the lowest-cost option.
Will WhatsApp and iMessage keep working?+
Yes. Both are tied to your phone number, not your SIM. If you keep your number, your chats and groups carry on with no migration. With a new local number, you would have to update your WhatsApp account and tell everyone the new digits.
What if a local service insists on an in-country number?+
Some local rentals or part-time jobs prefer a local number. Modern phones hold more than one eSIM, so I would keep your real line on Ringo for everything important and add a cheap local prepaid line for that one requirement. Your bank and family still reach you on the number you kept.
How much data will I actually need as a student?+
It varies with how much you stream and tether. Maps, messaging and browsing are light, while lecture videos and hotspotting a laptop are heavy. I would pick a plan sized for a full month of normal use rather than a short holiday allowance, since you will be living there, not visiting.