I'm the one gets the bill when my son buys something on his credit card.
I receive the charges for my son's purchases on the credit card our family uses.
ーI'm the one gets the bill when my son buys something on his credit card.
「息子がクレジットカードで何かを買うと、私に請求が来る」
to get the bill で「請求が来る」と言えます。
ーI receive the charges for my son's purchases on the credit card our family uses.
「家族クレジットカードでの息子の買い物の請求が私に来る」
to receive the charges で「請求金額を受け取る」を使っても言えます。
ご参考まで！
カナダ 
