EA discontinued its Online Pass system for its current and past games, including the FIFA series, as of 2014. Any games released after this occurred don't require an online pass.
EA eliminated the online pass requirements from many games that were released before the online pass was discontinued. For past games that still require online passes, EA offers free online passes in the Xbox Live Marketplace and the Playstation Store.
The online pass was a unique code that came with EA games. The player entered the code to access online features. However, players that purchased used games with a used code had to either play without those features or purchase a new code. Player feedback regarding online passes was one reason EA discontinued them.