I sent an invite to a client that I pay the subscription for, but he got a free trial which then ended and is now being asked to sign up with a subscription.

Hello Kay-thompsonciut, thanks for posting on the Community page, so it sounds like your client has 2 accounts one that the client created and has taken out themselves and one that you the accountant has created and made for them.  So it is a case of speaking with the client and seeing which one they want to keep going forward.