I overheard someone saying i didn't have to apply for the night rating as the CPL comes with one
Firstly, it's not a rating, it's a qualification. However, good question.... LASORS simply says that during CPL training if you don't already have a Night Qual you shall receive the 5 extra hours training. In such context it seems perfectly feasible that you could get away with just paying for the CPL issue and get the Night Qual by default.