It's easy to file an account! (6)
I believe the answer is:
facile
'it's easy' is the definition.
(synonyms)
'file an account' is the wordplay.
I cannot quite understand how this works, but
'an' could be 'i' (Roman numeral for one) and 'i' is present in the answer.
'account' could be 'ac' (abbreviation for account) and 'ac' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for facile that I've seen before include "A piece of cake" , "Over-simple, superficial" , "Lacking depth, argument say" , "Too easily achieved, glib" , "Superficial or too easily achieved" .)