Less than half (48 percent) of Brits understand what 'SIM-only' contracts are when it comes to mobile phones, says Simonlyoffers.com.

According to the mobile phone contract comparison site, just 21 percent of mobile phone owners were aware that a 'SIM-only' contract, which offers a bundle of minutes and text messages but no handset for a monthly subscription, could work out 50 percent cheaper than a handset inclusive deal.

"SIM-only deals have been available for around 18 months, so are a relatively new concept," said Richard Patterson, marketing director for Simonlyoffers.com.

"As mobile phones become more advanced, with even the cheaper models having more functionality than many people will ever use, there will be less need to upgrade a handset every eighteen months or so as is now the norm."

The website also said through keeping hold of their existing handsets or buying the phone they want independently in order to take out a SIM only contract, phone users can not only significantly reduce their monthly tariffs costs, but they will also enjoy shorter contract lengths, which can be as low as 30 days.

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