Do invited musicians need a paid plan to accept bookings and submit invoices?

No. Musicians can use the Free plan to accept bookings and submit invoices through Hot Giggity. They do not need to upgrade solely for those activities.

An invitation for someone new to Hot Giggity may start with Join Hot Giggity. They then create their account, complete the musician profile and accept the relevant invitation.

If the process appears to require a paid subscription, contact support with the screen you are seeing. You can review plan options under Manage → Account Settings → Membership.