Borrowers need not pay a second premium to a new lender for mortgage insurance on their home loan if they switch funders, the Treasurer, Wayne Swan, proposed in the Government's banking policy package yesterday.The plan is to make LMI policies - which are paid for by a lender, with costs passed to the customer in most cases - transferrable. Whether this will become industry practice needs a legal nudge and is something that is still to be worked out.Rebates may, in any event, prove an easier option to administer.QBE and Genworth already offer rebates to borrowers in some circumstances, though awareness of this option is low.The twist in the Government plan is that it is likely, in theory, to increase the cost of mortgage insurance policies, by extending the life of each policy.