Is it ethical to include team-based agency work in my portfolio?

[Btaliat]

It is not a big deal doing that. There are some instances where the freelancers can just add some tasks from team-work. Doing this, however, needs you to be honest. You need to let your clients know that you are not the sole owner of the work. You may even include your or state your particular aspect of the tasks. This will let them know that you are honest and can make them to patronize you.