What's the difference between having to show your ID and not having to show your ID?
この場合、次のような言い方ができますよ。
ーWhat's the difference between having to show your ID and not having to show your ID?
「ID提示が必要な時とそうでない時の違いはなんですか?」
What's the difference は between で続け、What's the difference between A and B? のように言うと良いですよ。
to show one's ID で「IDを見せる」
ご参考まで!