No, because the money in your offset account is only used to reduce your interest charge. Your repayments stay the same.  What effectively happens is that a larger portion of your repayment is applied to the principal portion of your loan rather than what previously would have gone towards interest. This provides major benefits to your overall costs as it will reduce the amount of total interest payable by allowing you to pay off your principal faster and therefore finish your loan off sooner than the initial agreed term of what likely would have been 25 or 30 years.