eSIM vs roaming vs local SIM: what Australians should actually buy
The maths is usually simple, but it flips completely on trips under about four days.
By Jamie · 7 min read · Published 3 May 2026 · Updated 3 September 2026
Australian roaming is sold as a day pass. Telstra, Optus and Vodafone all charge somewhere between $5 and $10 a day to use your normal plan overseas, capped at a daily data allowance.
That's the number every other option gets measured against.
The maths
A two-week trip on an Australian day pass costs $70-$140. A 15-day, 10GB eSIM for Japan, Thailand or Vietnam is usually under $15. For a fortnight in Asia, the eSIM saves you the better part of $100 per person.
The maths flips on short trips. A three-day Singapore stopover on a $5-a-day roaming pass costs $15 and requires zero setup, keeps your number live for calls and SMS, and doesn't need you to fiddle with settings on landing. That's a fair trade.
Rough rule: under four days, roaming usually wins on convenience. Over a week, an eSIM almost always wins on price.
What an eSIM actually is
An eSIM is a digital SIM you install by scanning a QR code. Your phone holds it alongside your Australian SIM, so both are live at once. You use the eSIM for data and keep your Australian number for calls and SMS.
That last point matters more than most people realise. Almost every travel eSIM is data-only. It doesn't come with a phone number, which means it cannot receive SMS. If your Australian bank sends one-time codes by SMS - and most do - you need your Australian SIM to stay active and reachable. Keep it in the phone, keep roaming enabled for SMS, and turn off mobile data on it.
Your phone also needs to be carrier-unlocked and eSIM-capable. Every iPhone from the XS onwards and most flagship Androids since the Pixel 3 support eSIM. Phones bought outright in Australia are almost always unlocked; some older carrier-financed handsets aren't.
Choosing between providers
The eSIM market has consolidated around a handful of resellers who all buy wholesale from the same local networks. What differentiates them is pricing structure, not coverage.
Airalo has the widest country coverage and the most consistent app. It's the safe default.
Holafly sells unlimited-data plans with a daily fair use policy. Worth it if you tether a laptop or stream heavily; poor value if you use 500MB a day.
Nomad and Ubigi compete on long-validity plans - 30 days or more - which suits a slow trip better than a 15-day plan you have to top up.
Saily frequently undercuts on the popular 10GB tier.
Rather than picking a brand, pick the shape of plan you need - how much data, over how many days - then compare across providers on that basis. That's what our per-destination eSIM comparisons are built around.
Regional plans
If you're visiting more than one country, a regional plan is almost always better value than several country plans. A Southeast Asia plan covering Thailand, Vietnam, Malaysia, Singapore and Indonesia typically costs barely more than a single-country plan, and a Europe-wide plan covers 30+ countries for the price of an Italy-only one.
Two special cases
China. This is the big one. A local Chinese SIM sits behind the Great Firewall, so Google Maps, Gmail, WhatsApp and Instagram won't work. An international roaming eSIM usually routes your traffic through a gateway outside China, which means those services keep working. Check the provider says this explicitly before you buy - it's the difference between a functional trip and a frustrating one.
The UAE. WhatsApp and FaceTime voice and video calls are blocked on UAE networks regardless of which local eSIM you buy. Messaging still works. An international roaming eSIM may keep calls working; ask the provider first.
Before you leave Australia
Buy and install the eSIM at home while you're on wi-fi, but don't activate it until you land - most plans start counting validity from activation, not purchase. Save the QR code and the installation email somewhere you can reach without data.
Then check the coverage note on your destination page. Rural coverage varies enormously between the local networks each eSIM resells, and it's the one thing the price comparison won't tell you.
Frequently asked questions
Will a travel eSIM work on my phone?
Every iPhone from the XS onward and most Android flagships from 2020 onward support eSIM. The phone also has to be carrier-unlocked. Australian phones bought outright usually are; phones still on a carrier plan sometimes are not, so check before you fly rather than after you land.
Do I keep my Australian number when I use an eSIM?
Yes. A travel eSIM is a second line, so your Australian number stays active for calls and SMS, including bank verification codes. You turn data roaming off on the Australian line and let the eSIM carry the data.
Is an eSIM actually cheaper than Telstra, Optus or Vodafone roaming?
Almost always on trips longer than about four days. Australian day passes run roughly $5 to $10 a day, so a fortnight is $70 to $140, while a regional eSIM is often $10 to $25 for the whole trip. Below about four days the day pass can work out cheaper once you count the setup.
Can I make normal phone calls on a travel eSIM?
Most travel eSIMs are data-only, which is fine for WhatsApp, FaceTime and Google Maps but will not dial a hotel or a local taxi. If you need real calls, either keep your Australian line on for outgoing calls at roaming rates or buy a plan that includes a local number.
When should I install the eSIM?
Buy and install it at home while you are on wi-fi, because activation sometimes needs a working connection. Do not activate it until you land: most plans start counting their validity from activation, not from purchase.
What happens when the data runs out?
You top up in the provider's app, which needs a connection. Keep a small buffer, or leave your Australian roaming available as a fallback so you are not stuck offline trying to buy more data.
