Bill is welcome? Do this to show it! (4,2,3,3)
I believe the answer is:
pick up the tab
'welcome? do this to show it' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'bill' is the wordplay.
I cannot really understand how this works, but
'bill' could be 'tab' (tab is a kind of bill) and 'tab' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for pick up the tab that I've seen before include "Assume the expense" , "Pay for something" , "Pay the whole bill" , "Foot the bill" , "Pay everyone's bills" .)