If a loan that has real estate tied to it is paid off, can it be used as collateral on another loan without filing a new mortgage?

This, of course, is a question best asked of your bank's local counsel. In general terms, however, while there may be an unusual case, it seems the better - routine - practice is to file a release of mortgage when the original debt is paid off and file a new mortgage for the new debt. Consider the following:

1. If the original mortgage does not have a future advance clause, it will not cover the new debt (unless a written modification agreement is recorded).

2. Even if the old mortgage has a future advance clause, to my knowledge you would not gain any advantage by using the old mortgage (rather than filing a new one), in terms of the priority of your mortgage interest in the property over other creditors.

3. Oklahoma law requires mortgage holders to file a release of mortgage within 50 days of the payment of the debt secured by the mortgage. See Title 46, Section 15 of the Oklahoma Statutes. This law also carries money penalties if (after the 50 day period) the mortgage holder fails to file the release within 10 days of receiving a written request from the mortgagor.

4. The old mortage could become unenforceable as to the new debt if it is not extended in accordance with Oklahoma law. See Title 46, section 301.

I'm sure that there may be other considerations, but hopefully the above information is helpful.