Goes back for tax documents (7)
I believe the answer is:
returns
I believe this is a double definition.
'goes back' is the first definition.
(returning is a kind of going back)
'tax documents' is the second definition.
(I've seen this in another clue)
'for' acts as a link.
(Other definitions for returns that I've seen before include "Sends back" , "Brings or comes back" , "proceeds" , "Goods sent back" , "profit" .)