The most common and most likely answer to this crossword clue is the 5 letter word DEBTS
I've seen this crossword clue in The Guardian
D
E
B
T
S
More clues leading to the result DEBTS
Buddy explains!
The straight part
We know that "what’s owing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what’s owing = debts.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DEBTS mean?
DEBTS noun- An action, state of mind, or object one has an obligation to perform for another, adopt toward another, or give to another.
- The state or condition of owing something to another.
- Money that one person or entity owes or is required to pay to another, generally as a result of a loan or other financial transaction.
- An action at law to recover a certain specified sum of money alleged to be due.