What is the Device Limit on DRM account and how is shared between Main- and Sub-accounts

When a specified quantity of DRM licenses is purchased (available licenses), this is reflected in the Device Limit and can be checked in DRM  at System > Accounts clicking on the Main account id:

This value cannot be changed manually but only by purchasing additional licenses.

The Registered Devices instead, reflect how many devices are currently added to the Account. (So those are the "used" licenses)

Digi grants the overall total licenses to the Main account and if the DRM account is set up with sub accounts, an user with Administator rights for the parent account could set a limit of licenses on each Sub account created (Note: by default when a subaccount is created, it will have the device limit set as the device limit of the Main account).

This is just an enforcement that states for this sub account they can not use more then the allowed quantity, but, that subaccount can use up to that quantity ONLY IF they are available on the overall account total of licenses on the platform granted to the main account.

In other words, the quantity set for each sub-account is not enforced by Digi but the overall total of licenses that can be used  between Main account and all sub accounts can not exceed the overall total paid from the parent account.

Example: 

• A Main account (Cst ID xxxx) has  purchased 25 licensees, so the total of all used licenses can not exceed 25. 
• This Main account has 10 Registered devices.
• The Main account has also 3 Sub accounts and for each has allowed up to 25 Licenses:
  • Sub-account 1:
    • Device Limit = 25
    • Registered Devices "= 5
  • Sub-account 2:
    • Device Limit = 25
    • Registered Devices "= 5
  • Sub-account 3:
    • Device Limit = 25
    • Registered Devices = ?

This status can be also checked in the System > Accounts (when logged in with the Admin user of the Main account):

So, ideally, the Sub account 3 is allowed to add up to 25 devices but will not be able to add more than 5 as the Total Registered devices between Main and Sub accounts, has already reached the quantity of 20.
This also mean that the 25 limit that is set on each subaccount is not subtracted from the total available for the main account until one or more devices are really added to that subaccount.