You can change the license type for your managed users at all times, but do keep in mind that the change will only take affect after the current billing period.
For example: if you change the yearly license to a montly license after 3 months of usage of the yearly license, the license will be a monthly license after the yearly license period.
- log in at myNomadesk.com
- go to manage
- go to billing -> License Overview -> click the Manage link next to the license that you want to change
- change the license type to your preferred type
- click save