An agency may request that money payable from the Fund be offset to recover any valid debt due the United States when all of the following conditions are met:
    
    
        
        (a) 
         The debtor failed to pay all of the debt on demand, or the creditor agency has collected as much as possible from payments due the debtor from the paying agency; and
     
    
    
        
        (1) 
         Obtaining a court judgment for the amount of the debt;
     
    
    
    
        
        (4) 
         Following the procedures agreed upon by the creditor agency and OPM, if it is excepted by  § 845.405(b)(4) from the completion of procedures prescribed by  § 845.405(b)(3).