..Where do I find my NVC case number and invoice ID number? The National Visa Center (NVC) will send you both of those numbers. After NVC receives your approved petition from USCIS, NVC creates a case file for you at the Department of State and assigns you an NVC case number. NVC will send you a letter or e-mail with your case number and a separate invoice ID number. Keep in mind that you cannot begin to pay fees or submit documents until you receive this letter from NVC instructing you to begin processing.

alright so I have to go back and check then

i guess so i got that from google @do road