Arrears highest north of Sydney 14 December 2009 5:37PM Philip Bayley Fitch released its "Australian Mortgage Delinquency by Postcode" report to September 2009 and observed that some areas like western and south-western Sydney will be under increased pressure as interest rates rise. The report shows that the worst performing postcode is Nelson Bay, on NSW's mid-north coast, both in terms of dollar value and number. The Gosford-Wyong region is the worst performing region.