A contractual provision that gives the lender the right to demand repayment of the entire loan balance in the event that the borrower violates one or more clauses in the note.

Bankapedia's Take

So what could possible make a bank "call your loan" . In the current market (2009), pretty much nothing if you are paying on time, or if you are paying anything. As long as you are paying something and haven't abondoned your home, your mortgage, and don't have vagrants squating in your house, the bank will not call your loan, regardless of what is stipulate in the acceleration clause.

All of this being said, when the market returns to normal here are a few Items that will cause you have your loan called:

• The Listed Borrower not being that is actually paying the mortgage. If the loan is in John Smiths name, but they get a check from Danny Appleseed every month, the bank is going to assume its not John paying the mortgage. To them, this means that John might be unable to pay and if Danny stops paying they collect nothing at all. So pre-emptively they call the mortgage. This may also mean that John no longer lives there and has had someone assume the mortgage. If the Lender allows for an assumable loan this is no longer an issue

• The Borrower Dies Yup, if someone dies the bank will typically call the mortgage. Or if the person is in a reverse mortgage, the bank already owned the house and simply stops making payments. Typically when someone dies and money is owed on the house, the bank will work with the family and give them a few months to sell the property so the bank can get their money back and the family their equity.

• Missed Payments As stated before if the Bank is underwater on the loan ( your home is worth less than the loan) they will not call the loan as long as you are paying them something, even if you are late. However, if the bank gave you a low rate, your home is worth far more than the loan, they would love to have you out of your house, take your equity and put someone else in the mortgage that will pay a higher rate and on time.
•