The period of time, prior to closing of your house purchase ("the completion date") that a lender will guarantee that the interest rate they have offered will not rise. This is usually for a period between 90 and 120 days - although longer rate holds are available under special conditions. The commitment letter will also state under what conditions (if any) that they will decrease the interest rate if and when rates in general drop prior to your completion date.

When property taxes are included with your mortgage payments, your lender will hold back funds from your mortgage proceeds to cover interim or final property taxes payable to the municipality. The amount depends on the month the mortgage was funded and on the dates when interim and final taxes are due. Holdbacks are used to pay for the current year's taxes, while your monthly tax installments are accumulated in the account to pay for the next year's taxes.