Sanction account, the thing’s getting in red (8)
I believe the answer is:
accredit
'sanction' is the definition.
(thesaurus)
'account the thing's getting in red' is the wordplay.
'account' becomes 'acc'.
'the thing' becomes 'it'.
'getting in' is an insertion indicator.
'acc'+'it'='accit'
'accit' placed around 'red' is 'ACCREDIT'.
(Other definitions for accredit that I've seen before include "Red cacti (anag)" , "Trace CID and send them with credentials" , "Show to be correct" , "Attribute (something to)" , "Cat cried (anag.)" .)