Withdraw H1B visa application while in RFE to go back to H4/EAD

[shreya_dallas]

I am currently on an H4 visa with approved EAD. My H1B got picked in lottery this year and is currently in RFE. I want to withdraw the H1b application because of my travel plans. Any idea if I can withdraw my H1B application now/even after approval?
Also how long does it take for USCIS to notify that application has been successfully withdrwan?