Put down “Time to pay membership fee” (6)
I believe the answer is:
subdue
'put down' is the definition.
(thesaurus)
'to pay membership fee' is the wordplay.
I cannot quite understand how this works, but
'membership fee' could be 'sub' (I've seen this before) and 'sub' is located in the answer.
The remaining letters 'due' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'time' is the link.
(Other definitions for subdue that I've seen before include "Vanquish" , "Bring under control, tame" , "Quash" , "Overcome or inhibit" , "Overcome, suppress" .)