The most common and most likely answer to this crossword clue is the 6 plus 8 letter word NUMBER CRUNCHER
I've seen this crossword clue in Financial Times
N
U
M
B
E
R
C
R
U
N
C
H
E
R
Buddy explains!
The straight part
We know that "accountant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case accountant = number cruncher.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.