Mozo guides

How to use your mobile phone overseas

Low angle view of couple in 20s and 30s sightseeing in Barcelona and smiling as they look at smart phone with Sagrada Familia in background.

When you’re planning on travelling overseas, there’s a lot to think about. You might need to compare travel insurance, sort out travel money cards, find accommodation and flights, and more. But one of the more overlooked parts of travelling is working out if you’re going to be able to use your phone (and mobile phone plan) overseas. 

You should be asking yourself two questions: will my phone even work in another country and is my mobile phone plan suitable for travelling?

The two main factors here are your phone’s compatibility with local networks in your destination country and, if your phone is locked into a specific telco provider (e.g. Optus, Vodafone or Telstra). 

How to check if my phone is compatible with overseas networks

In Australia, we use GSM technology. Luckily, this type of mobile network is pretty standard across the world. This means that in most parts of Europe, Asia, the United States, the United Kingdom, and New Zealand, you should be able to jump on the local networks. 

However, there are always cases where compatibility will be an issue. So, make sure you do a bit of research to determine if the networks at your destination run on GSM. If they don’t, then they’ll likely be CDMA networks, which your phone might not be compatible with.

Some countries, like the US and Japan, use a mixture of both GSM and CDMA, and some phones are compatible with both networks too. So, it’s really a case-by-case matter of if your phone will work in another country. 

How do I know if my phone is locked to a provider’s network? 

If you bought your phone outright, or as part of a postpaid plan, then it’s likely to be unlocked already. This means you can swap out your Australian SIM card for an overseas prepaid SIM easily, without having to unlock your mobile phone. 

If you bought your phone with a prepaid SIM, there’s a good chance that it will be locked to one mobile phone provider (Telstra, Optus, or Vodafone in most cases). 

To unlock your phone from your service provider’s network, the process can differ. In each case, you’ll likely need to pay an unlock fee, between $25 to $80, depending on how long you’ve had your phone.

Can I use my mobile phone plan overseas?

If you’re with one of the big three Australian telcos (Telstra, Optus, or Vodafone) then the answer will often be a resounding yes. However, the international roaming options from these guys are optional extras that can cost between $5 and $10 per day, with small data limits. So use Wi-Fi networks whenever possible to save on top-ups! 

Telstra, Optus and Vodafone international roaming packs differ in terms of prices, eligible destinations, and data inclusions. 

If you’re with one of the smaller telcos (MVNOs), you may not have the option to add international data roaming to your plan. 

It’s also crucial to note that international roaming can be quite costly, especially if you go over your data limits. Even making phone calls back home to Australia from an overseas destination can be significantly more expensive – especially if you’re used to a mobile phone plan with unlimited talk and text. 

In many cases, it might be easier (and cheaper) to simply pick up a new SIM card that works in the countries you’re visiting.

What options for SIM cards do I have when travelling overseas?

Young hipster couple looking at a smart phone in their kitchen

If you’ve decided to purchase a new SIM card for your travels, you’ll have three main options: local SIM cards, international SIM cards, and travel SIM cards. 

Local SIM cards

Local SIM cards can be bought once you’ve landed in your destination and will usually only work for that country. 

Local SIMs can be cheaper than using international data roaming, plus you should be able to choose roughly how much talk and text you want to include in your plan. 

Think of local SIM cards like a pre-paid SIM you’d buy from the servo. Quick and easy to set up, local SIM cards are available all over the place – from corner stores to airports. 

International SIM cards 

As you might have guessed, international SIM cards are similar to local SIMs, but work across multiple countries where the mobile provider operates.  

Travel SIM cards 

Travel SIM cards are pre-paid plans and can be bought before you leave Australia. These types of SIM cards are designed to provide mobile phone coverage in a broader range of countries than international SIMs. 

Travel SIM cards can be set up before you travel, meaning you won’t be scrambling to find a SIM card in a country where you mightn’t speak the language. 

Travel SIMs, as a trade-off for their convenience, can be more expensive than local and international SIMs.

Travelling with only free Wi-Fi networks

If you’re really looking for a budget-trimming way to use your phone overseas, or if the SIM you purchase over there expires, then you can always utilise free Wi-Fi networks. 

Hotels, cafes and restaurants, major attractions, and cities often have free public Wi-Fi networks that you can take advantage of. And you won’t only be saving on data roaming costs, as you can also use Wi-Fi for talk and text, with apps like WhatsApp, Viber, and Skype all being viable, free options for keeping in touch over the internet. 

However, public Wi-Fi networks are less secure than your personal home network, for instance. So, make sure you consider the following: 

  • Wi-Fi - trust the provider of the Wi-Fi network (e.g. your hotel, a reputable chain of cafes/restaurants). 
  • HTTPS - avoid websites that are not HTTPS encrypted (Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge will warn you). 
  • Personal info - don’t give away too much if you need to sign up to use the Wi-Fi. 
  • AirDrop - turn this off.
  • VPN - use when possible for personal data encryption. 
  • Software - make sure your device’s software is up to date.

How to find public Wi-Fi networks 

There are several websites and apps that can help you find free public networks to connect to, such as WiFiCafeSpots (web), Wiman (mobile), and Instabridge (mobile).

Want a new SIM for your adventures abroad (or at home)? Make sure you compare mobile phone plans with the right amount of data for your needs for wherever you’re going. Check out some of the deals on offer below.

Mozo may receive payment if you click to the website of one of the products below currently available via our partner, WhistleOut. They do not compare the entire market, but you can see more options by clicking on the View Full Results link in the table.
Last updated 22 July 2024
Jack Dona
Jack Dona
Money writer

Jack is RG146 Generic Knowledge certified, with a Bachelor of Communications in Creative Writing from UTS, and uses his creative flair to cut through the financial jargon and make home loans, insurance and banking interesting. His reader-first approach to creating content and his passion for financial literacy means he always looks for innovative ways to explain personal finance. Jack's research and explanations have been featured in government publications, and his work is regularly featured alongside major publications in Google's Top Stories for Insurance.