Talk talk.

A guide for spelling things over the phone:

It's helpful if the following letters are followed by an "as in..."

B as in boy
D as in David
F as in Frank
G as in girl
M as in Mary
N as in Nancy
P as in Peter
S as in Sam
T as in Thomas
V as in Victor
Z as in Zebra

All numbers and remaining letters are generally understandable without further clarification.

This should save considerable time and stress for both you and the person with whom you are talking.


Also, if the person on the other end of the line says, "I'm having trouble hearing you" and nothing is amiss such as a broken microphone or your face being an abnormal distance from the phone, that would then be your cue to speak up.