Ok, firstly check your watering....is it too dry or too wet, if that's ok, how long has it been in that pot ?

Do you feed it ? Luckily, Fatsias are pretty hardy and will weather the storm so to speak.

The lower leaves of Fatsia do go yellow but if it's in a pot perhaps transplanting to a large size would help.

And they do prefer a little shade, rather than full sun.

Thank you for the replys
I did think that perhaps it was over dry as I went on holiday and I thought I maybe have over watered it when I came back. So maybe a combination of those?
It's been in the same pot since I bought it last year.
Should I put it in a bigger pot and move it to somewhere with a bit more shade?

Yes and yes to both your questions in the last paragraph! Needs more root room, and they do very well in shady spots.

Thank you. That's my job for tomorrow sorted