Lenders need to be more proactive with customers if they want to slow down the high rate of mortgage run-off the industry is currently experiencing, according to an industry consultant.The managing director of RFi Advisory, Alan Shields, said there was a lot that banks could do. And they needed to act because more borrowers are planning to take advantage of low interest rates and increase their prepayments."Lenders know the average life of a loan and they would know when loans are coming up to that anniversary. At that point they need to contact the customer," Shields said.Lenders reported double-digit growth in loan approvals during the December half, but some have struggled to achieve any growth in their mortgage portfolios, as a result of higher prepayment levels and run-offs.Research that RFi conducted with Macquarie Securities found that older borrowers on low and middle incomes were keen to increase their repayments, as were young borrowers on high incomes.On a state-by-state basis, prepayment is more common in South Australia, Victoria and Western Australia.RFi and Macquarie found that the proportion of homebuyers and property investors who said they planned to make additional mortgage payments increased from below 50 per cent in June last year to around 55 per cent in December 2013.Westpac reported that in the December quarter of 2012 new mortgage lending was A$11.7 billion, while run-off was $9.3 billion. In the March quarter last year new lending was $14.7 billion and run-off was $10.5 billion. In the June quarter new lending was $14.9 billion and run-off was $12.4 billion. And in the September quarter new lending was $17.8 billion against a run-off of $13 billion.Bendigo and Adelaide Bank reported that home loan approvals were up 13.5 per cent in the six months to December but its loan book grew by just 2.5 per cent. bankmecu reported that 85 per cent of its home loan borrowers were ahead with their repayments, with the average about 21 months in advance of their repayment schedule. Westpac's group executive for retail and business banking, Jason Yetton, said: "We have looked at what triggers run-off so we can be more proactive with customers. Those triggers include the age of the loan, a change in valuation of the property and fixed rate loans maturing." Shields said: "Being proactive is the key. Lenders should be able to work out what's going on by looking at the borrower's behaviour. Are they making bigger repayments? Have they stopped putting their salary into their transaction account? Have they stopped spending on their credit card?"