The most common and most likely answer to this crossword clue is the 5 letter word TRIES
I've seen this crossword clue in The Daily Telegraph
T
R
I
E
S
Buddy explains!

The straight part
We know that "taxes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case taxes = tries.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 TRIES mean?
TRIES noun- An ordered tree data structure that is used to store an associative array where the keys are usually strings.
- An attempt.
- An act of tasting or sampling.
- A score in rugby league and rugby union, analogous to a touchdown in American football.
- A screen, or sieve, for grain.
- A field goal or extra point
- To attempt; to endeavour. Followed by infinitive.
- To divide; to separate.
- To test, to work out.
- To experiment, to strive.
- To lie to in heavy weather under just sufficient sail to head into the wind.
- To strain; to subject to excessive tests.
- (used with another verb) To want