The most common and most likely answer to this crossword clue is the 7 letter word BACKLOG
I've seen this crossword clue in The Guardian
B
A
C
K
L
O
G
More clues leading to the result BACKLOG
- Support record showing work not yet completed
- Finance account in arrears
- Unfinished work in finance, something to burn
- Finance record reveals arrears
- Support needed on journal, work piling up
- Support wooden person in tasks still to be dealt with
- Result of slow work in second part of plane, perhaps
- Reserves support look good
- Second record’s a heap of work to get through
- After blackout attempt to return to work piled up
Buddy explains!

The straight part
We know that "arrears" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case arrears = backlog.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 BACKLOG mean?
BACKLOG noun- A large log to burn at the back of a fire.
- A reserve source or supply.
- An accumulation or buildup, especially of unfilled orders or unfinished work.
- A log containing text previously read, as in text-based video games or chat rooms.
- To acquire something as a backlog, or to become a backlog