Travel tips: Everything you need to know about data, global roaming and SIM cards

Data. Small, four-letter word but for most travellers when they head offshore it's a big deal. How else are you going to update your emails and social media feeds, stream music and video, stay in touch with free VOIP calls, find your way and all the other advantages that total connectivity conveys?

The basic choice is whether to access data services by replacing your SIM card or relying on free Wi-Fi, and both strategies have their appeal.

For anyone with a smartphone, replacement SIM cards that allow you to make phone calls from overseas are almost incidental. Data is what you need. Data is not just the icing on the cake, it's the whole cake. Not only does data give you a fully functioning suite of apps, it also lets you make all the calls you need using VOIP with an app such as Skype or WhatsApp.

Should you decide to stick with your everyday Aussie telco's SIM card, you're turning off data roaming on your smartphone, are you not? Fail to do this and as soon as you land in foreign climes your phone will begin chirping to Facebook, Twitter, Snapchat and all those other apps on your phone and the extent of your folly will be revealed with your next phone bill.

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Buy a data plan

Most Australian telcos now have global data plans that cap the cost of roaming.  Activating one of these plans is as simple as logging onto your telco's website. You may even be prompted along this path when you activate your device upon landing in another country. If it's a short stay you might be tempted to take this easy road. However they're not particularly competitive, especially if you're away for more than just a few days.

Telstra's Travel Pass, available to its customers on a plan, costs from $15 for three days of data, capped at 225Mb. This price applies only to Telstra zone 1 country, and the only country  in that zone is New Zealand.  Much of the world – the USA, the UK, Germany, Canada, France, Italy – falls into Telstra's zone 3, which will cost you a pricey $45 for a three-day Travel Pass, $105 for a week with a cap of 525Mb rising to an eye watering $450 for 30 days of data, capped at 2.2Gb.

Optus customers on a monthly mobile broadband plan can pre-purchase an Optus Travel Data Pack for $10 per day for 70 Mb of data daily in Optus' zone 1 countries, which includes NZ, North America and practically every country in Europe and North America you're ever likely to visit. I tried this on a trip to Italy in October and it was rubbish. The Travel Data Pack I pre-purchased wasn't operating when I arrived and despite a call to Optus I was never able to establish a connection with a local data service, and this was in Rome.

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Buy a local data SIM card

If you want to access data over the local network at rock-bottom prices, this is the way to go. Some countries make you jump through a few more hoops than others, for example requiring a passport and a local address to buy a prepaid SIM, but they're a cheap way to access data and stay in touch, particularly if your data requirements are reasonably high. In Italy after my experience with Optus I bought a prepaid SIM card from TIM, a leading Italian telco, at a cost of €20 for 3Gb plus phone calls, valid for one month. In Hong Kong the same month, a  Discover Hong Kong Tourist SIM card bought from the airport and widely available at convenience stores, valid for five days with 1.5Gb of mobile data, cost just HK$88. Basic to this is the assumption that your phone is unlocked. If not, you're out of the game.

Buy a multinational data SIM card

These all sell on the premise that they'll work anywhere in the world, with the usual exception of parts of Africa and a small handful of paranoid dictatorships such as North Korea and Turkmenistan. Providers include GO-SIM, which sells its 200Mb data SIM for $44. TravelSIM has a variable cost structure between 25 cents and $1 per Mb depending on location, while WorldSim Worldwide Data SIM card will set you back anything from 16 cents/Mb to a stratospheric $11.85/Mb if you have the misfortune to need data services in Swaziland. In some countries they work like a charm, most of the time, in others they're completely useless. If connectivity is crucial 100 per cent of the time, they're not totally reliable.

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Turn it off

It's amazing just how available free Wi-Fi is when you you're out and about in the world these days. Airports, hotels and many cafes and restaurants will let you hook up for the price of a cup of coffee, or zero cost. Even some towns in Europe have local Wi-Fi hot spots where you can log in for free. If you choose this no-worries option, since you've got your native SIM card still in place, with global roaming turned off, you should still be able to send and receive messages in most of the world at a modest price, and the folks back home can get in touch if they need to.

Apart from instant access to emails, social media, stock market updates, news reports and weather updates there is only a handful of apps that require 24/7 data connectivity for most leisure travellers, and they're marginal at best. One is GPS maps, but you can use an offline GPS map app such as Sygic or download Google Maps in many cases to make them available offline. If you're driving you'll miss out on traffic reports that might cause you to modify your route but this may not be a deal breaker.

Another is the voice function on Google Translate. You can still download an entire foreign dictionary so you can say "Please pass the salt" in Kurdish, you just can't hear it spoken.

Data protection

Hooking up to the internet via unfamiliar Wi-Fi hotspots can leave you exposed to hackers. Airports and cafes popular with travellers are a favourite place for cybercriminals to create false internet pathways. Log on via one of these networks and all your files and browsing activity are transparent. Any usernames and passwords you enter will be known. You can target-harden your online browsing if you turn off file sharing and network discovery, enable your firewall and use a VPN client to browse, which encrypts traffic and makes it more difficult for a potential hacker to intercept. If yours is a Windows-based machine make sure your network setting is "Public".

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