Trying to get reviews for Clients

I am creating a landing page for my clients. The process goes

1) Send Invite to client and client goes to landing page

2) There’s a link on this page for my clients to send to their customers to get reviews

3) Client will need create a Review Generator (something like Google's)to create the review and post to the clients page on my marketplace

Basically - How do I ensure that the feedback link from the customer is uniquely affiliated with the correct client? is there a SaaS or API hat i could use?

Note: Using RoR