The most common and most likely answer to this crossword clue is the 9 letter word RETAINERS
I've seen this crossword clue in The Times
R
E
T
A
I
N
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More clues leading to the result RETAINERS
Buddy explains!
The straight part
We know that "amounts paid in advance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case amounts paid in advance = retainers.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 RETAINERS mean?
RETAINERS noun- Any thing or person that retains.
- A dependent or follower of someone of rank.
- A paid servant, especially one who has been employed for many years.
- A fee one pays to reserve the other's time for services.
- A device that holds teeth in position after orthodontic treatment.