Are grounds for getting authorisation (7)
I believe the answer is:
warrant
I believe this is a double definition.
'are grounds' is the first definition.
(thesaurus)
'authorisation' is the second definition.
(I've seen this before)
'for getting' is the link.
(Other definitions for warrant that I've seen before include "Writ for arrest" , "Guarantee" , "Permit for arrest, search of premises, etc" , "Call for" , "Document giving authority" .)