Roaming costs can quickly soar while using your mobile phone overseas. Assuming your mobile phone carrier provides overseas roaming of course (not all do). In this article, we’ll take a look at some of the cheapest ways you can use your device overseas.

Check your phones network compatibility

First off, it’s important to check that your device supports phone carrier networks in the countries you’re travelling to.

This is less of an issue these days as most countries support GSM standard devices. GSM - or Global System for Mobile Communications - is a standard that was developed by the European Telecommunications Standards Institute.

This means it’s likely your device (especially if it’s a recent purchase) will work in countries like the USA, New Zealand, Australia and the UK and much of central Europe. Your mileage may vary in other countries, so be sure to investigate thoroughly prior to departure.

Check if your carrier supports mobile roaming

If you’re heading overseas from Australia and you want to be able to use your existing phone number, check to make sure your carrier supports mobile roaming in your travel destination.

Telstra, Optus and Vodafone all support international roaming on most plans. However not all plans support this, and some smaller telco providers don’t support roaming at all.

If your carrier doesn’t support mobile roaming, then you won’t be able to use your Australian phone number overseas. But you could explore transferring to an alternate carrier or plan prior to departure.

Alternatively, you could look at purchasing a travel SIM as discussed below.

Enable mobile roaming

If you want to use your Australian phone number while overseas, make sure you check with your carrier to ensure mobile roaming is enabled.

From Australia, all three major carriers offer mobile roaming on most post-paid plans. Vodafone offers the best deal. On supported plans, you can get access to the same plan allowances that you have in Australia for just $5 per day.

Optus also offers roaming starting at $5 per day on select plans. This includes 5GB of data per day in more than 100 “Zone 1” countries, as well as unlimited standard talk and text even in remote locations like Iceland.

Telstra offers an international roaming “day pass” on many of its plans, but pricing per day varies between countries. You only get 1GB data per day for countries in zones 1 and 2. Additional data costs $10 per GB.

Buy a pre-paid travel SIM

If you’re out of luck and your carrier or plan doesn’t support roaming - or it’s too expensive - then buying a pre-paid SIM might be the better option. Often you can get a better deal with more data at a lower cost by buying a local SIM card via a reseller.

Getting setup is easy if your device supports eSIMs (most recent iPhones and many flagship Android devices) and you’re still using a physical SIM card for your Australian phone service.

Many pre-paid travel SIM sites such as SimsDirect and Travelex offer eSIMs for many countries around the world. This means you can be up and running as soon as you arrive at your travel destination!

And if your device doesn’t support eSIMs then on most sites you can continue to buy physical SIM cards. Note that you’ll need to plan in advance for this, as postage means it may take a couple of weeks for your SIM card to arrive.

Keep in mind that you may still want to explore having your Australian phone number accessible overseas. This is especially important if you’ve advised your airline of your Australian number for travel updates, or if you need access to things like two-factor authentication codes via SMS for online services such as banking.

Use Wi-Fi wherever possible

Plan to use Wi-Fi wherever you can, as this will almost always be cheaper than using mobile data while travelling. Most resorts and many travel destinations have Wi-Fi available these days.

Wi-Fi is great for bandwidth-intensive activities like uploading photos or videos that you’ve taken to the cloud, or FaceTiming with friends and family while you travel.

Just make sure you use a VPN if you’re connecting to free, public Wi-Fi so that hackers can’t sniff your network traffic.