Sanction account, the thing's getting in red (8)
I believe the answer is:
Here is my best explanation:
'sanction' is the definition.
'account the thing's getting in red' is the subsidiary indication.
'account' becomes 'acc'.
'the thing' becomes 'it'.
'getting in' means one lot of letters goes inside another.
'accit' going around 'red' is 'accredit'.
(Other definitions for accredit that I've seen before include "Appoint", "Accept as true", "Give official recognition to", "Recognise", "Cat cried (anag.)", "Certify, ascribe", "Show to be correct", "CID trace (anag.)", "Trace CID and send them with credentials" and "Authorize".)