Nickname is not subject to change. However you players can request nickname change only when meeting the following conditions:
Real name is used mistakenly
The nickname can be used to identify personal information
How to request a nickname change
1. Tap the Pokeball-shaped icon
Tap the icon at the center bottom of the screen.
2. Tap the setting icon
Tap the icon at the top right corner of the screen.
3. Tap Help Center tab
4. Tap 'YES'
5. Tap 'Submit a request'
6. Tap 'Request a nickname change'
7. Tap 'Request a nickname change' again
To move to request submission display, tap the link.
8. Enter the name and submit
Enter your email address and the name currently used, and submit the form.
How long will the nickname change take?
The request will take a few weeks to be accepted.
Tips for naming
Add a number to the name if it is unavailable
If the name you want to use is used already by someone, add a number into the name. However, avoid using a number which can be used to identify your personal information, such as your birth day.
Convert uppercase letters to lowercase and vice versa
Uppercase letters and lowercase are different in Pokemon Go.
Must not use the name can be used to identify personal information
Since Pokemon Go use your location information, using the name can be used for identifying personal information may cause trouble.
How to change an avatar's outfit
An avatar's outfit can be changed whenever you want
Changing an avatar's out fit is available due to the recent update. Tap the link below to see how to do that.