Broadband provider iiNet now offers customers the option to bundle in a contract-free mobile phone plan, with unlimited access to Facebook and Twitter.

iiNet Mobile operates on the Optus network, which covers most of Australia, and is exclusive to iiNet broadband customers.

The plans are available from $10 a month, which includes $150 monthly call value, 200MB of data and unlimited social network access.

iiNet Mobile also offers a $20 plan, which includes $400 in calls, 500MB of data and unlimited social network access. Finally, for $40, customers can make $750 of calls, use 1.5GB of data and unlimited social network access.

The plans are BYO, so customers will need to provide their own handset.

In order to prevent customers suffering from bill shock, iiNet Mobile will let customers know by text message and email when they are approaching the data or call limit.

There is also a $150 limit for mobile usage outside of the plan value and once exceeded, the service is restricted. Customers who want the restriction lifted can contact iiNet Mobile.

iiNet offers ADSL2+, ADSL, bundle and Naked DSL services to customers. Plans start from 10GB and range up to 1,000GB. iiNet also offers its own modems, including the popular BoB and the new BoB Lite, as well as VoIP and IPTV services.