due-bill

from The Collaborative International Dictionary of English v.0.48

Duebill \Due"bill`\, n. (Com.)
   A brief written acknowledgment of a debt, not made payable to
   order, like a promissory note. --Burrill.
   [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

DUE-BILL. An acknowledgment of a debt, in writing, is so called. This 
instrument differs from a promissory note in many particulars; it is not 
payable to order, nor is it assignable by mere endorsement. See I 0 U; 
Promissory notes.