Closed Period

A period of time, often 10 years, after issuance of a bond when that bond cannot be called. See also Callable.

The term during which a mortgage cannot be Prepaid. Often found in mortgages on commercial property, but seldom in residential mortgages. The mortgage is assumable by subsequent buyers of the property.
Example: A mortgage on an office building for $10 million at 8% interest had a 10-year closed period. After it was originated, interest rates generally dropped to 6%, and the borrower wanted to pay it off and refinance, but this was prevented during the closed period.