If you have a Standard Chartered bank account you can pay at the ATM. Take your bill and ID to your nearest SC branch to register the bill details on your account. After a couple of days it shows up under the "Bill Payment" option on the ATM.

Saves you having to withdraw money, looking for an MPesa outlet to add funds to your MPesa account etc. 

And SC do not charge at all so you pay no transaction fees as far as I know.

Bill Payment is perhaps the only thing that SC have got on point these days.