UKBA has warned applicants that online visa application forms are only valid for 30 days from the date that they started the process. 

Any application that is submitted which is more than 30 days old will not be accepted and applicants must start the process again.  If an application is rejected on this basis, this could lead to migrants being in the UK without valid leave, which could jeopardise both their own legal status and place their sponsor at risk.