I amm / it is
In a letter is the use of "I am Peter" as incorrect as on the phone?

Should I say " it is Peter " Or it is not a good thing to say ?

Thanks

Question

I amm / it is
In a letter is the use of "I am  Peter"   as incorrect as  on the phone?

Should I say  " it is Peter " Or it is  not  a good thing to say  ?

Thanks

Answer

If you are introducing yourself in a letter you would say, 'I am...'.

When you answer the phone you say 'This is...'

Answer

When we talk about ourselves we say "I am"
When we talk about someone/ something else we say "it is"

Mary asks Peter "Who are you?" " I am Peter."
Mary asks Jane. "Who are you talking to on the phone?" " It is Peter"