To be paid (5)
I believe the answer is:
owing
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">to be paid</span>' is the definition.<br/ ><span class="explanation-format__explanation">(eg an unpaid bill is owing)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for owing that I've seen before include "Unpaid" , "Outstanding as a debt" , "Unsettled; on account" , "This debt has yet to be paid" , "(Of money) outstanding" .)