Mobile roaming is still one of the biggest bugbears for any company that has an international workforce. In spite of efforts by the European Union and other international bodies to cap the amount that mobile network operators can charge customers for using their mobile phones abroad, companies around the world are still regularly forking out for exorbitant phone bills.

Juniper Research expects operator revenues generated from mobile roaming to exceed $80 billion by 2017, compared to over $46 billion this year. These revenues will largely be driven by increasing data usage, which will account for over 40 percent of total usage ($35 billion) by 2017, according to senior analyst Nitin Bhas.

However, there is an expectation these days that people are constantly connected and, for most business employees, switching off their mobile phone while abroad is simply not an option. This means that, until regulations come in to abolish international roaming charges, most consumers and businesses just have to suck it up.

No more roaming charges

One company trying to overcome the problem of international roaming is Truphone, a mobile virtual network operator (MVNO) that offers customers standard local rates rather than roaming rates in countries where it has partnerships with local operators. There are currently four “Truphone countries” – United Kingdom, United States, Australia and the Netherlands.

Truphone works by piggybacking on local mobile networks in each country. It does not own the radio access network, but it owns everything else, including the home location registers (HLRs), the short message service centres (SMSCs), the gateway GPRS support nodes (GGSNs) and the session border controllers (SBCs).

This allows it to run its patented multi-IMSI technology, which holds multiple phone numbers on a single SIM card. (An IMSI is an identifier, a bit like an IP address). So a user could have a UK number, a US number and an Australian number all on the same SIM, and when that user calls an overseas contact it will be as if they are calling from a local number.

Furthermore, when the user travels to a Truphone country, the mobile network will recognise the IMSI for that country, and allow the user to make local calls at local rates. Unlike other international MVNOs, which require the user to switch off their UK number, switch on their US number, and forward all of their UK calls to their US number, Truphone is able to switch automatically over the air.

Truphone’s service is not limited to the countries where the company has established local networks. It also provides discounted roaming in over 220 countries worldwide - similar to the ‘bolt-ons’ offered by mainstream mobile operators. These are grouped together by continent, so a user can sign up for a “EU27” bundle, an “Americas” bundle or an “Asia Pacific” bundle.

Testing in the 'Truphone zone'

I tried out Truphone's service over a two-month period, during which time I visited the United States, Spain and Turkey. The company provided me with a breakdown of my spending for comparison with my existing T-Mobile contract.

I was put on Truphone’s “Individual 500” tariff, which includes 500 minutes, 500 SMS and 500MB of data for £40 per month. This compares to £33 per month for my current T-Mobile plan, which includes 2,000 minutes, unlimited texts and unlimited UK data.

For a more like-for-like comparison, Truphone Individual 2000 (which includes 2,000 minutes, 2,000 SMS amd 2,000MB data) costs £60 per month, but this is currently only available in the UK.

Where Truphone really comes into its own is in so-called Truphone countries. On my visit to the US I made 15 minutes of calls to the UK, sent 7 texts to US numbers and used 68.7MB of data, and everything was included in my Truphone contract.

By contrast, T-Mobile would have charged me £18 for calls, £3.50 for texts and £50 for data. Together with fairly minimal usage in the UK, my total Truphone bill for for the month came to £46.87, compared £121.37 with my current T-Mobile plan, making Truphone the clear winner.

Outside of Truphone countries, however, things are a little less clear-cut. During my week in Spain, I made 63.3 minutes of calls to the UK, sent 57 texts and used 384.8MB of data. Spain is not currently a Truphone country but is due to become one later this year, along with Germany, Poland and Hong Kong.

With Truphone, the calls cost £12.66, the texts cost £3.99 and the data cost £90 (based on buying a 500MB roaming bundle for use in the EU27), which is a total of £106.65 on top of the monthly plan.

By comparison, the calls on T-Mobile would have cost £18.23, texts would have cost £5.07, and data would have cost £70 (based on buying two 200MB boosters), which is a total of £93.30 on top of my monthly plan - bringing it in cheaper than the Truphone contract.

Once Spain becomes a Truphone country, however, all of the calls, text and data will be included within bundle, so again Truphone will come out on top.