Relinquishing tax charge (7)

I believe the answer is:

cession

'relinquishing' is the definition.
(cession is a kind of relinquishing)

'tax charge' is the wordplay.
'tax' becomes 'cess' (I've seen this before).
'charge' becomes 'ion' (an ion is a charged particle).
'cess'+'ion'='CESSION'

(Another definition for cession that I've seen is " Act of surrender".)

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app