Follow the below step by step procedure;
1.Go to your phone’s M-Pesa menu.
2.Select Lipa na M-Pesa
3.Select Pay Bill
4.Select Business no
5.Enter the Prime Bank bank’s PayBill number 928800 and press okay.
6.Select Account number.
7.Enter the bank account number you intend to send the money to and then press okay.
8.Enter the amount to deposit
9.Enter your M-PESA PIN
10.Verify information and press okay.
A confirmation SMS is received on phone.You are good to go