回答
-
Could everyone please pay on one bill?
-
Could everyone please pay together?
「みんなんでまとめて払ってください。」は
1) Could everyone please pay on one bill?
2) Could everyone please pay together?
と言えます。
もし「個別会計はできません。」と言うなら
Sorry you can't pay individually.
Sorry you can't each pay separately.
などと言えます。
ご参考になれば幸いです!