Making calls, sending texts and using the mobile internet while you're abroad can be costly.
Headlines showing British holidaymakers getting stung by hefty charges they weren't aware they were racking up, have made a lot of people feel pretty uneasy about using data abroad.
Fortunately, many networks are now offering competitive price plans to make these horror stories a thing of the past.
Below we take a look at each network in turn to see what's on offer.
I've heard roaming charges are being scrapped. Is that true?
The European Union has voted to completely remove roaming charges by June 2017, meaning you'll pay no more than you would in the UK to use your smartphone, as long as you are in an EU country.
In the meantime, charges for phone use in EU nations are being reduced gradually.
Although leaving the EU could increase prices for British travellers, the cost of data, calls and texts shouldn't be affected in the short-term.
From April 30th 2016, networks are charging five cents (about 3p) per minute for a call, two cents (just over a penny or so) for a text message and five cents (once again, about 3p) for a megabyte of data downloaded.
However, all networks have their own add-on packages for those going away either on holiday or business. These entitle you a set amount of calls, texts and data overseas for a one-off charge.
Find the right one for your needs and it'll hugely help you cut your outgoings on overseas phone usage.
Here we take a look at them in turn to see what's on offer and pick out the overseas phone usage bundles we think are the very best on the market.
Three’s ‘Feel At Home’ offer is by far and away the best deal for those looking to use their smartphone abroad.
There are 42 countries where you can use your at–home allowance of calls, texts and data without paying extra and without having to tell Three you’re going away.
These are in Europe and beyond, including USA, Australia and New Zealand. You can see the full list of countries here: Three Feel at Home.
Three claims that Feel at Home saves customers an average of £202 per trip.
Calling numbers within a country will cost extra. But you'll be notified of the rates by a text message from Three when you arrive at your holiday destination.
Just be aware that not all EU countries are included at this time.
However, from 15th June 2017, Three is set to expand its range of countries covered by the scheme to 60.
It's worth nothing that Feel at Home is reserved for customers on Three's Advanced Plans.
If you're on a Three Essential Plan, you'll still be able to use your allowance for no extra charge in the EU from 15th June. But you won't qualify for free roaming in locations further afield.
To find out how much you could save, use the special calculator on Three's website.
Three also has a £5 per day Euro Internet Pass for other destinations.
Vodafone has just launched two new global roaming schemes for new and upgrading pay monthly customers. Roam-Free lets you use your regular monthly allowance of calls, texts and data in 40 European countries for no extra cost. Roam Further allows you to access your monthly allowance in 60 countries for an additional £5 per day.
It's worth bearing in mind that in order to qualify for Roam-Free and Roam-Further, you'll need to be a new customer or an existing customer who upgrades to a new plan.
For existing customers, Vodafone offers two key packages for using your phone or tablet abroad.
Its EuroTraveller deal allows you to make calls, send texts and access the web for £3 a day in 40 countries, although as with Three this only includes your UK allowance. Making local calls costs extra.
Its WorldTraveller package offers those heading away on long–haul trips the same deal, but for £5 a day.
This includes 58 countries, which you can see in full at Vodafone's dedicated page.
However, it's worth noting that to use WorldTraveller you need to be a Pay Monthly or business user.
O2’s Pay Monthly customers can stump up £1.99 per day to use data in Europe as part of the network’s Pay & Go Travel deal.
39 destinations are included, with allowances ending at 11.59pm each day.
However, O2 charges 3.6p per minute to make calls to the UK or within Europe and it's free to receive. Texts cost 1.2p to send.
From 15th June, O2 customers will be able to use their monthly allowance of calls, texts and data from anywhere within the EU for no extra cost.
EE has a wide range of packages available for travellers. These are split into all–round deals for calls, texts and web access and simple data plans for those who want to access maps and other web–connected services.
£4 per day will get you calls, texts and data in 47 destinations as part of its EuroPass. As with other networks, this is limited to UK allowances.
Making calls to numbers in the country you are in will cost extra. You only need to text 'EUROPASS 150' before you leave.
Travellers to the United States can pay £3 extra for access to the mobile web, or opt into a bolt–on as part of their monthly contract. Find out more here: EE roaming in the USA.
And from 15 June, all existing EE pay monthly and pay as you go customers will get inclusive roaming to 47 European destinations as part of their mobile, mobile broadband or tablet allowance. This will work in the same way as Three’s Feel at Home scheme, by letting you use your monthly allowance of calls, texts and data in any EU country for no extra cost.
EE has also introduced a new range of 4GEE Max plans for new and upgrading customers that allow customers to use their monthly allowances across 52 destinations worldwide. These include EU countries as well as the USA, Canada, Mexico, Australia and New Zealand. This covers over 80% of time EE customers spend overseas, and currently includes more destinations than any other network.
Virgin Media offers a number of Travel Passes.
These start at 35p for 10MB of data, rising to £1.50 for 50MB of data and £6 for 250MB.
While the pass does last thirty days, the reality is that 10MB of data will be used up within a matter of minutes on any modern smartphone.
For us, that fact means Virgin’s roaming packages aren't as impressive as its rivals' offerings.
You can check them out for yourself here: Virgin Media roaming packages.
From 1st June 2017, all Sky Mobile customers will be able to use their mobile data, calls and texts in 36 European locations for no extra cost.
For customers with Unlimited Calls and Texts as part of their plan, all calls to landlines and mobiles and all texts sent within the EU are included.
If you're on Pay As You Use calls and texts, you'll pay the same rate as you do in the UK.
The other big benefit of Sky Mobile as far as roaming goes is that if you've already stored a trove of unused data your Sky Piggybank, you can use the data when you're in Europe too.
So which is best?
Of all the major networks, Three is probably the standout provider when it comes to using your phone abroad.
Vodafone has excellent packages which cover a broad range of destinations, while EE’s service is decent.
O2 and Virgin aren't bad by any means. But they have a lot left to do if they want to be up there with their rivals.