British Passport Fees Payment Slip and Grand Parents detail

hi all member of forum
I want to apply my Son British Passport i have got his British registration certificate while fill up the application form i have noticed that there is no any Payments Slip to pay the Passport fees
and shall i need to write grand parents detail as well like date of birth place of birth and date of marriage
any senior member please guide that how and where i have to pay the passport fees and what other documents i need to send with application i am sending followings:

British Registration Certificate
all Previous Foreign Passport
Two photographs

is that all i need to send or some thing else like my ILR and passport copy etc

Miangee wrote:hi all member of forum
I want to apply my Son British Passport i have got his British registration certificate while fill up the application form i have noticed that there is no any Payments Slip to pay the Passport fees
and shall i need to write grand parents detail as well like date of birth place of birth and date of marriage
any senior member please guide that how and where i have to pay the passport fees and what other documents i need to send with application i am sending followings:

British Registration Certificate
all Previous Foreign Passport
Two photographs

is that all i need to send or some thing else like my ILR and passport copy etc

payment slip is in the guideline booklet inside the passport application envelope.