The most common and most likely answer to this crossword clue is the 4 letter word TASK
I've seen this crossword clue in The Guardian
T
A
S
K
More clues leading to the result TASK
- Contract's ending, then request a job
- Job in test, as keeper
- Ending on benefit, request job
- Time to request church working party
- Time to request a bit of work
- Starter for ten — question for Labour
- Works a treat, reversing to include charge
- Volunteers risked having cover blown twice in assignment
- Undertaking pilot’s last request
- Job centre in Stockport was located on turning
Buddy explains!

The straight part
We know that "charge" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case charge = task.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 TASK mean?
TASK noun- A piece of work done as part of one’s duties.
- A difficult or tedious undertaking.
- An objective.
- A process or execution of a program.
- To assign a task to, or impose a task on.
- To oppress with severe or excessive burdens; to tax.
- To charge, as with a fault.
- Second sight; the involuntary ability of seeing the future or distant events.
- The sound of the voice of a person about to die, heard supernaturally by somebody not present at the scene.