The specialist sim only comparison site http://www.simonlyoffers.com has seen a 60% rise in sales over the last 6 months.

Richard Osbourne, Marketing Director at Sim Only Offers cites a number of reasons for the growth stating: "We have seen an increase in the number of sim only deals which have been backed by an increase in advertising spend to promote these offers to consumers who are looking to tighten their belts since the economic downturn."

Osbourne explains that there are a number of advantages to sim only deals compared to standard mobile phone contracts. Sim only contracts, as the name suggests, involve getting only a new sim card and keeping your existing phone and phone number with the provider passing on much of the cost saving (on a new handset) to the customer. Sim only contracts are typically much shorter in length than standard mobile contracts where the cost of the phone needs to be recouped over a lengthy contract.

Osbourne cites the new 3GS iPhone as an example which is only available on 18 or 24 month contracts through O2 whereas SIM only contracts are typically 30 days. The cheapest monthly price on an 18 month contract with a bottom of the range iPhone 3Gs (the 8GB model) from the O2 website is GBP29.38 per month plus a charge of GBP96.89 for the phone and includes just 75 minutes of UK calls and 125 UK text messages. By comparison O2's cheapest sim only deal costs just GBP9.79 which includes 150 minutes plus 300 texts with a contract of only 30 days.

Osbourne predicts that the growth in sim only contracts will continue as awareness is raised that those who are happy to keep their existing mobile handset can find a significantly better deal with a sim only contract. With 3 Mobile recently entering the sim only market Osbourne predicts that the increased competition will further drive down prices making these offers an even better proposition for UK consumers.