Anyone playing Pokemon X & Y who thinks it’s easy to complete the Kalos Pokedex may want to think again as any Pokemon that is from a different Pokedex will not be counted.
One gamer said that he found this out when he got the oval charm and certificates but he didn’t complete the Pokedex as he had a Buizel that came from an older gen.
He said that he got around this though by catching the Kalos version of that Pokemon. So gamers should be aware that they can only complete the Pokedex if they catch Pokemon from the Kalos region that have been hatched there.
So it does look as though completing it is harder than first thought as while you could complete it on your own before, now you can benefit from having friends playing with you.