So far, we’ve used the example of a 100 percent offset account, in which the whole balance of the account is applied to the home loan. A partial offset account, on the other hand, simply lowers your interest rate by a portion of the amount in your offset account. For example, putting $50,000 in a 50 percent partial offset account would save the loan $25,000 in interest.
As a result, partial offset accounts are less common and, in general, less successful in assisting you in repaying your mortgage. If possible, look for a mortgage with a 100 percent offset account.