It's fine, a little informal. Use it with people you know.

You've been given excellent answers on this question. I would like to add that in my region "later" is VERY informal and considered slang...as in "later dude". I never use "later" unless I am just being silly with friends. I use "see you later" all the time with people I know..my friends, my boss,...basically everyone. I typically use "goodbye" when on the phone with someone I don't know. "Bye" is fine to use as but it is less formal than "goodbye". Here's my breakdown: 1. "goodbye" is the most formal 2. "See you later" = "Bye" (these are equal in that they work in the same situations) 3. "later" - least formal (Personally, I would not use...depends on the region I guess)

later is abbreviation of, see you later or talk to you later. It is little informal like Randy said..Native speakers will understand you but every English speaker may not understand it. Bye, on the other hand is a very standard and understood-by-all word. Hope this helps

Later means afterwards i.e. not now. Later and bye are not synonyms, some people might use them interchangeably though.