WHEN a loophole appeared last year that allowed people to make free international calls from mobile phones, the industry swiftly closed it. Not surprising when you consider that Vodafone’s standard rate for 20 minutes to New Zealand is £26.

Yet a new trick resurrects free calls overseas for those with “free minutes”. Everyone else can benefit from paying local call costs.

Which system you can exploit depends on your network and how much hassle you are willing to undergo.

The old loophole still works for most Orange contract customers; everyone else can choose between a slightly fiddly system for free calls or a simple system for dirt-cheap ones.

To clarify, this is to make calls from your mobile phone in Britain to overseas phones, not to UK mobiles abroad.

Orange’s easy trick

Orange customers with a contract that includes free minutes to other mobiles can access a clever scheme operated by niche specialist telecoms providers, including simply-fone.com, dialabroad.co.uk and planettalkfree.co.uk.

You dial their access numbers, which begin with 07744, from your mobile to connect to their network and then dial the overseas number you are calling at no further cost.

Normally you would be charged for calling the access number, yet on Orange these numbers are part of your free calls allowance, so there’s no charge to you.

Numbers starting 07744 once belonged to a now-defunct mobile-phone network. These specialist operators bought the right to use these numbers and get a cut of the call cost when you dial them. But with Orange these 07744 calls are free to customers.

Not every country can be called this way, but Europe, North America, Australasia and some parts of the Far East are usually covered. Each provider varies slightly so it’s worth checking them all.

This should work on the vast majority of Orange contract tariffs, but to be safe try it for the first time with a short call and then check your bill online or wait for your statement to ensure that the access call is free.

This trick used to work for all networks, but the rest now exclude 07744 numbers from their free minutes. At some stage Orange may join them. If that happens, just start using one of the methods below.

The Rebtel route

Rebtel (rebtel.com) has a clever system that allows you to make calls to 37 countries from your mobile phone, mainly in Europe, North America, Australasia and the Far East by dialling a local-rate access number. If you are entitled to free minutes on your mobile you won’t pay anything for the call. Otherwise you’ll pay a local call rate.

Because it’s a little fiddly to use and the call quality is not great, it’s best reserved for friends and family you phone regularly. But the savings make it worthwhile.

A 15-minute call to America is free rather than the £15 charged on O2’s standard rate, for example. Here’s how it works:

Dial a local-rate access number provided to get connected to the people you are calling and ask them immediately to call the number they see displayed on their mobile. You have only 15 seconds to do this. If they are on a landline, Rebtel will send them an e-mail for the first call. The same number is then usable each subsequent time. The number will be a local one in their country.

Stay on the line and once they dial the access number they will automatically be connected to you.

Each person gets 10 free calls a month where you can talk as long as you like. After the 10 calls you are charged only for the first minute of each subsequent call, no matter how long you speak. For example, you pay just 1p to call an American mobile or 2½p for an Australian one.

Rebtel has come up with a really clever ploy here. It, of course, hopes that once you’ve used its free service, you’ll use some of its other, paid-for, services too.

No-hassle calls

An easier route, which is not free but very cheap, is to set up an account with a specialist cheap-calls provider. This has the advantage that every country is covered. Most can be used only from landlines, yet three sister companies – 18185, call18866 and 1899 – and Rebtel offer special services for mobiles.

You access the service by dialling a local-rate number, meaning it’s included in any free minutes you have. You then dial the overseas number you want. The provider will bill you for the call. To call India for 20 minutes using T-mobile, for example, the standard cost is £26, but via call18866 it’s £3 plus the cost of any local-rate access call.

- Martin Lewis is a broadcaster and creator of Moneysavingexpert.com, a free website dedicated to showing people how to save money