My number has changed

[david11]

My friend sent me a SMS saying My number has changed.

Shouldn't it be My number has been changed?

Thank you.

 

[5jj]

Either is possible.

 

[david11]

Either is possible.

which one is formal or more accurate?

 

[billmcd]

My friend sent me a SMS saying My number has changed.

Shouldn't it be My number has been changed?

Thank you.

Either is OK. But for me and in your example, "has changed" could mean that the number was changed by her, at her request or by another party/agency. Whereas "has been changed" has a slight inference that the number was changed by another party/agency.