OnePlus X and OnePlus 2 can now be purchased without an invite
 

When OnePlus released its first phone back in 2014, it pulled off an interesting publicity stunt. Buyers could only order its One phone if they obtained an invitation first. OnePlus is finished with this invite system for the moment, and it's come up with a clever new idea to replace it: send the company money, and it'll send you a phone back.

http://techreport.com/news/29661/one...hout-an-invite