Fee for Citizenship

HI, I am Britiah by Descent. My wife and two daughters came 3 yers before. Last yer they got ILR. Now I am going to aplly for Naturalisation of my wife (Form AN) and registration of my two daughters under (Form MN1) sec 3(5).
I am confused if I need to pay their fee separatley using separate fee form for each or I can pay on one form. As paying for two children is a bit cheaper. (1 child £673 and two £1178)On the fee form it asks the applicant name and Date of Birth etc....

You can pay on one form, and include the main applicant's information. Ensure all the application forms are submitted together with that fee form.

Thanx a lot.