The most common and most likely answer to this crossword clue is the 5 letter word TRONC
I've seen this crossword clue in Financial Times
T
R
O
N
C
More clues leading to the result TRONC
Buddy explains!
The straight part
We know that "To which some patron contributes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to which some patron contributes = tronc.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 TRONC mean?
TRONC noun- A monetary pool, in which tips are collected and later shared out between all staff, e.g. in a restaurant.