You can purchase additional licenses/seats for $400 USD per user per year. This will provide an unlimited access to the entire Coursera for Business catalog for 12 months.
You will most likely add users at various points throughout your contract year. The amount you pay will be prorated daily if the original plan was purchased after January 29, 2020*. This means that you will only pay for the remaining portion of the current contract year, then the seats will renew on the same date as the originally purchased seats.
*Due to partner restrictions, if your original plan was purchased before January 29, 2020, daily proration for added seat charges apply only up to the first 6 months of the contract year. This means that adding a seat at any point in the latter 6 months of the year will cost $200USD for access through the remainder of the contract year. (e.g. if you purchased the plan on Oct 1 2019 and add a seat on Sept 1 2020, it would cost $200USD for 1-month access until all seats renew together on Oct 1 2020).