Invites always safer than an account but if you have to deal with an account. You should take the original email with it, how?

1. The one who gave you the account will make another email and put it as the email of that tracker's account. Then he'll give you the username and password of the account + the new email and password.

2. You must not change anything immediately after you get inside, because they'll notice many things changed in short time. "IP, email, password"

3. Most trackers don't allow you to change your username, i think it's ok if the same username on other tracker with different IP.

4. I don't recommend you to use someone's account, especially if it's strict tracker.

The point is it depends on what tracker you are looking for. And also try to find invite instead of acc.