Clue: Untidy employees making a contribution to Warwickshire's coat of arms (6,5)
Answer: RAGGED STAFF
Explanation: Definition: a contribution to Warwickshire's coat of arms
RAGGED (untidy) + STAFF (employees). The coat of arms of Warwickshire features a bear chained to a ragged staff. Very weak clueing of the "ragged" part of the phrase, I'm afraid