Often, my friends and I will " chip in" -- or pay jointly for a fun night out. When we go to restaurants, the meal is " Dutch treat" -- each person pays his or her own share.
"Going Dutch" is a term that indicates that each person participating in a group activity pays for themselves, rather than any person paying for anyone else, particularly in a restaurant bill. It is also called Dutch date, Dutch treat (the oldest form) and "doing Dutch".