Teachers Mutual Bank has introduced a mortgage offset facility that is available with all its mortgage products, including fixed-rate and interest-only loans. Offsets are a standard feature with variable rate loans but are not otherwise widely available.The offset works through the bank's Everyday and Everyday Direct transaction accounts. It is a full offset, with the transaction account balances netted off the mortgage balance when mortgage interest is calculated, and interest on the transaction account balance credited to the mortgage account.Teachers Mutual Bank's chief executive, Steve James, said the bank started selling mortgages through brokers last year and received some feedback about its products, including a call for an innovative offset facility.A TMB member with two or more mortgages can have offset accounts to match each mortgage. "Our members now have market-leading flexibility," James said.Infochoice lists 27 lenders offering offsets with fixed-rate loans. However, all but nine of them have conditions limiting the effectiveness of the offset.Some offsets only apply to one-year fixed rates (not longer terms) and others are only available after the fixed-rate period ends. Partial offsets are common with fixed-rate loans, where a reduced interest rate is charged on the portion of the mortgage equal to the balance of the offset account.