when dialing a number, it ask for 1 letter

[Android Central Question]

After dialing a phone number, I have to enter an ID number which includes letter H. How do I switch from numbers to the Letter

 

[B. Diddy]

Welcome to Android Central! Do you mean that after the call goes through, you have to enter an ID code to an automated system? Letters would probably correspond to the appropriate numbers on a standard phone keypad. So the number 4 would be for G, H, and I.