to pay separately = tiền ai nấy trả
Let's go Dutch = Let's split the bill.
"The origin of the phrase “to go Dutch” is traced back to the 17th century when England and the Netherlands fought constantly over trade routes and political boundaries. The British use of the term “Dutch” had a negative connotation for the Netherlanders were said to be stingy. To “go Dutch” implies an informal agreement that each person will pay his or her own expenses during a date."