First of all dial a number you wish to store in the phone, If you wish to store in positions M1, M2 or M3 press STO after dialling the number then any of the positions. If you wish to store on numbers 1-0 then dial the number press STO followed by MEM then any digit, for example dial the number, press STO, press MEM then number 6. To speed dial any number stored lift the reciever, press MEM then any digit...Hope this helps