Getting the best mobile phone deal

7. Don't forget voicemail: Remember that calling your voicemail from abroad can cost the same as making a call to the UK - check with your provider if in doubt. Unlike at home, you may be charged every time someone leaves a message on your voicemail. If you want to avoid these charges, you can switch off your voicemail before you leave the UK.

8. Using mobile internet abroad: Be aware that when connecting to the internet via a mobile handset, dongle or data card (a portable modem which provides internet access via the 3G network) while abroad could cost significantly more than when using them at home.

9. The local SIM option: If you are out of the country for a long period time, it could be cheaper to buy a local SIM card that can be used in your handset or a local dongle.

10. Alert your operator immediately if your phone is lost or stolen: If your phone is lost or stolen when you are abroad remember that you could be liable for the cost of the calls made in that country. Make a note of the contact details of your operator before you travel to ensure that you can get in touch with them as soon as possible to report the loss.

Know your rights

There are a number of regulations that all mobile phone operators must adhere to which are designed to enable consumers to secure the most appropriate service from their provider.

• Operators are obliged to provide users with clear and up-to-date roaming charges and tariffs, for example through publication on their websites, television adverts or direct mail as well as informing new customers when subscriptions are taken out and existing customers each time there is a change in roaming charges.

• When customers travel between European Union member states, operators must automatically send a free message, which usually comes in the form of a text message, with information on charges for making and receiving calls and provide a free of charge number for obtaining more detailed information.

• Mobile operators must offer a standard 'Eurotariff' for those travelling to EU Member States where they can charge no more than 49 euro cents per minute (approximately 38p per minute) to make a call and 24 euro cents per minute (approximately 19p per minute) to receive a call. This has lead to an average reduction in charges of more than 50%.

• The default tariff for most customers is now the Eurotariff but any customers who are on a different tariff can request to switch to or from the Eurotariff at any time and operators must switch the customer within one day.

• Operators must give customers additional information on request and free of charge via text or free phone call on the per-minute or per-unit charges for downloading data and give clear information on the cost of making calls abroad.

• Operators are not obliged to inform customers of any unusual activity on an account. Therefore, if your mobile is lost or stolen it is important to contact your operator as soon as possible. Operators generally refund call costs if a stolen phone is reported lost within 24 hours. However, operators usually do this as a goodwill gesture and are not obliged to do so.

Consumers have contacted Ofcom with cases of 'bill shock' when returning from abroad including a consumer who bought a 5GB limit data roaming card prior to a trip to Austria and received a bill for over £4,000 for usage, after being informed that the operator's limit was only 50MB.

Another consumer used a mobile to surf the web whilst in France and was charged over £400 for 15 minutes of access, and another received a bill for £1,400 for using a portable modem to access the internet while on holiday in Egypt.

Ofcom's Chief Executive, Ed Richards said: "Ofcom is encouraging industry to bring down the price of texts and downloading data when consumers are abroad. This advice will help to ensure that consumers can get the best value for money when keeping in touch and downloading data whilst abroad, and avoid unexpectedly high bills on their return."