Tell tale to check tally (7)
I believe the answer is:
recount
'tell tale' is the definition.
'recount' can be an answer for 'tell' (synonyms). I'm not certain of the 'tale' bit.
'check tally' is the wordplay.
'check' becomes 're' (I can't justify this - if you can you should believe this answer much more).
'tally' becomes 'count' (synonyms).
're'+'count'='RECOUNT'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for recount that I've seen before include "reason for lateness of election result?" , "outcome of tight ballot?" , "possible action when votes are checked" , "Tell - check on election result" , "Communicate" .)