Bonds are automatically converted to Current Debt one day after they are due, January 1 of the following round (they are due December 31). Since you make decisions on January 1, if you tell your CFO to pay a bond that is due this year, you are actually telling her to pay the bond a year early at the current market price. If you do nothing, next round the bond will disappear from the list and Current Debt will increase by an amount equal to the face value.