An acceleration clause in a mortgage gives the lender the right to demand payment of the entire loan balance or perhaps require some other form of collateral which would defray any losses they may experience or fear they may experience.
Acceleration clauses are designed to protect lenders from landing in a situation where they lose great sums by supplying someone with a mortgage. It is not a clause designed to screw over the property buyer and the lender will not enforce the acceleration clause unless certain situations arise. Some of those situations include a loan default, the title is transferred to another person, the taxes aren?t paid, or the breaking of loan covenants. Each situation is a little different and the lender has the discretion whether to enforce an acceleration clause or not.
If there is an acceleration clause in your mortgage agreement this isn?t a reason to balk at the agreement. Unless you plan on defaulting or committing some other faux pas against the mortgage covenants then you probably will never run into a situation where the acceleration clause is called into effect. Remember the acceleration clause is a form of insurance for the lender, it is not designed to harm the buyer.