I have a kia cerato and was told that the fuel filter was in the fuel tank which I have never heard of before. Can anyone help me as to if this is true.

Unfortunately, most late model cars are like that now. They have a screen on the bottom of the fuel pump, located in the gas tank, and no separate filter.

It is in the fuel tank and you can find it when you remove the back chair in your car you will find a cover with 8 bolts unscrew them and gently pull the fuel pump set and replace the filter with a proper one