A mortgage acceleration clause is an important provision within the mortgage contract. It provides the lender with the ability to demand all of the remaining loan payments if the borrower happens to default on the loan. In effect, this is the part of the contract that gives the lender the right to foreclose on a property when the borrower fails to make his payments on time. The mortgage acceleration clause is an essential part of every single mortgage signed in the United States. The clause is typically written as a privilege of the lender. This means that the loan is not automatically accelerated when the borrower fails to make payments. The bank ultimately has discretion in how they choose to use the clause. Though they technically could choose not to accelerate the loan, most lenders will exercise this right whenever they are legally able to do so.