Company, they say, that takes anything back (3)
I believe the answer is:
two
'company they say' is the definition.
(as in 'two's a company, three's a crowd')
'anything back' is the wordplay.
'anything' becomes 'owt' (I've seen this before).
'back' says the letters should be written in reverse.
'owt' written backwards gives 'TWO'.
'that takes' is the link.
(Other definitions for two that I've seen before include "''... turtle doves''" , "Duo" , "1 + 1" , "Number in pair" , "Prime number" .)