In short - no!
Inviting your client or collaboration partner into your Sessionwire Studio is as simple as sending them your unique Invite Link.
Once your client/partner is in your Studio, they have access to all of the features that are available to you - if you are a Sessionwire Studio Basic member, they get all of the Sessionwire Basic features that you have. If you are a Sessionwire Studio member, they will have access to all of the Sessionwire Studio tier features while they are in your Studio.
Of course, nothing beats having a Sessionwire Studio account - so invite them to sign up for their free account and you can add them to your Connections list - then they'll be one click away from your Studio!