How do I create a Facebook account to manage advertising campaigns for my clients that complies with Facebook’s policies?
To manage clients accounts on the Facebook platform you should use Business.Facebook.com. At my advertising agency, I have my personal account set up as an administrator for my company Business Manager.
You can check out this page from the Facebook help files:
The basic point is that Facebook prefers that you connect with client account through the Business Manger. This allows you control of who has access and what level.
It also provides protection for the client, because they can disconnect you and keep their campaign data.
Facebook only wants you to have one personal profile, but allows you to connect and create many pages and ad accounts through the Business Manager.