My college has a Creative cloud membership, it also includes Typekit. When we build a website for a customer do we need a separate Typekit license when we use a Typekit font for this customer or can we use my colleges license for the customers website?
If you want to use Typekit on your clients' sites, you would need to upgrade to a Business Plan. Reselling to clients (using Typekit to serve fonts for client sites) is permitted on Business Plans only. We may limit the number of sites you can resell on each plan in the future, but for now the only limitation is for pageviews (which begin at 2M pageviews a month and go up from there).
You can learn more about our Business Plans (which also feature VIP support and guaranteed uptime) at the bottom of this page: https://typekit.com/plans/
You could also choose to purchase an individual Typekit account on behalf of each of your clients, or you might ask your clients to purchase the accounts which you can help manage.
I hope this helps; please let me know if you have any further questions.