Crossword Genius

Centrally imposed overtime, holder of innumerable letters — one's job (6)

Ross

I believe the answer is:

postie

'holder of innumerable letters one's job' is the definition.
I can't tell whether this defines the answer.

'centrally imposed overtime' is the wordplay.
'centrally' indicates the central letters.
'overtime' becomes 'tie' (I can't justify this - if you can you should give a lot more credence to this answer).
The central letters of 'imposed' are 'pos'.
'pos'+'tie'='POSTIE'

(Another definition for postie that I've seen is " Mail deliverer (informal)".)

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app