We’ve all experienced that flurry of text messages upon switching on our mobiles in another country? At the very least there will be one from your network provider warning you about possible additional charges while you’re outside your country of residence; another welcoming you to the local network linked to your usual service provider that also has information on charges and rates; and one with information about the 112 emergency services number.

Most people ignore these messages – but doing so can lead to a nasty phone bill surprise.

READ ALSO How to avoid huge ‘roaming’ bills when visiting France

If you have a French phone, here’s a look at where you can use it without worrying about extra charges.

EU countries

If you’re travelling within the EU, you’ll not face additional roaming charges for using your French phone in any of the 27 countries that make up the block.

That is; Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovenia, Slovakia, Spain and Sweden.

As Norway, Iceland and Liechtenstein are members of the European Economic Area (EEA), you will also be able to use your French phone there, too, without risking hefty roaming charges.

This provision also extends to the French overseas territories of Guyana, Martinique, Guadeloupe, Réunion, Mayotte, Saint-Martin, Saint-Barthélemy, and Saint-Pierre-et-Miquelon.

What about Switzerland?

There are, right now, no plans to adapt roaming charges for French mobile users in Switzerland. French users can therefore face roaming charges in Switzerland, but the rates are usually very low – it’s a good idea to check with your operator if you are travelling there regularly, however.

And the micro states?

Don’ forget that the EU also contains a number of tiny ‘micro states’ that are not full members – Monaco, Andorra and San Marino co-operate with the EU on a lot of things, but do not have free roaming.

Monaco uses the French train service so it’s not always immediately obvious when the have entered the tiny principality down on the Mediterranean coast, although you should get an SMS from your service provider so you can be reminded to turn off data services.

How long can I stay in another country without additional penalty?

The EU Commission legislation states that in order to pay for calls, messages and data usage at the same price as in your home country without additional roaming costs you must use the mobile phone for a longer period in your country than abroad.

Phone operators can track data consumption and roaming that their customers have used in the last four months. If during this time you have used more mobile services abroad in another EU country rather than in your home country, operators could legally apply small extra charges.

Non-EU countries

If you’re travelling outside the EU, everything depends on your network provider as roaming charges vary on a company by company – and country-by-country – basis. If you’re in doubt, check with your mobile provider before travelling.

Crucially, operators are required, as they are for users travelling within the EEA, to keep you informed of the prices charged as soon as you cross a border.

Furthermore, operators are required to cap overcharging for the use of mobile internet while roaming outside the EEA. The default worldwide cap is €60, unless a different ceiling has been agreed between customer and operator – that’s worth checking.

A warning message must be sent to the user when reaching 80 percent of the default or agreed cap as well as when reaching the limit. Beyond this limit, roaming downloading is blocked by the operator, unless expressly requested by the user.

This protection mechanism does not concern voice services, namely calls and SMS.

Post-Brexit UK

Since the UK has left the EU, it is no longer part of the free roaming arrangement. As such, phone companies decide for themselves whether they want to apply roaming charges.

So far operators in France have kept the United Kingdom in the list of countries included with the data quota in the EU zone. This means that whatever your operator you can make calls, send SMS, and use the internet from the United Kingdom without additional costs – although an increasing number of UK operators are applying roaming charges for France.

The French government’s line is to check with your service provider before you travel.

What about the US or Australia?

French carriers – certainly the Big Four, Orange, SFR, Bouygues, Free – generally offer special tariffs with data bonuses that can be purchased if you are travelling to the US, or other international destinations. 

You are likely to need to – even temporarily – switch to an international plan, or a specific USA Pass, to use your phone normally and access the internet in the US. Just make sure your international plan includes where you’re going among its list of destinations.

Even if you subscribe to an international plan, make sure that it authorises calls and mobile data use in the USA, otherwise that bill when you get back could be huge. 

As always, it’s always best to check with your company before flying out to the US, to find the best current available deals.