Thanks! Kiss dad, your common source of revenue! (8)
I believe the answer is:
taxpayer
'common source of revenue' is the definition.
I can't tell whether this defines the answer.
'thanks kiss dad your' is the wordplay.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'kiss' becomes 'x' (X can represent a kiss).
'dad' becomes 'pa' (both can mean one's father).
'your' becomes 'yer' (I can't justify this - if you can you should believe this answer much more).
'ta'+'x'+'pa'+'yer'='TAXPAYER'
Can you help me to learn more?
(Other definitions for taxpayer that I've seen before include "Contributor to national finances" , "One contributing to the Treasury" , "Extra pay (anag.)" , "Earner contributing to government funding" , "Government funder" .)