Adding Extra To Be Sure
Many times a person is unsure if he has repaid a loan in full (time has passed and he doesn’t remember, etc.).
May he add extra money to be sure he is fully paid up, or is that considered ribbis?
Contrary to what one may think, this rather common shailah is actually not a problem of ribbis.
One may add extra money to be sure that he is paid in full, since his intention is not to pay ribbis, rather to avoid any possibility of carrying an outstanding balance.