A unique identifier is how your domain or organisation is identified to service providers when users access resources. Whilst occasionally a numeric organisation ID they are more usually a scope and this looks like an internet domain - e.g.
Each domain will have a unique identifier and that is usually all that is needed - i.e. all subscription content is purchased for the whole domain.
Sometimes a domain is very large or widespread and has different resource needs for the organisations within it - e.g. sites in different countries. Where this is the case, the organisation can be set to have its own unique identifier and this allows the users under of that organisation to be seen by service providers as being represented by a different subscription. Specifically they will have their own scope but will still use the same federation entityID as the domain.
Advantages of a unique identifier for an organisation
- Organisations can subscribe to different content using their own budgets
- Subscriptions can be less expensive when a smaller number of users can access
Disadvantages of a unique identifier for an organisation
- Content associated with the domain's identifier cannot be accessed by users under an organisation with its own identifier unless the service provider is able to associate multiple identifiers with a subscription.
- The costs for several small subscriptions to the same resource can add up to be more than one large subscription
If in any doubt, talk it over with your account manager or your support provider.
Once you have made up your mind, your account manager or support provider will make arrangements to have the relevant sub-organisation enabled with its own scope - this will generally take the form of a number added to the main organisation's scope - e.g. 123579.organisation.net. Use of this kind of 'sub-domain' makes it much easier for providers to cover all your scopes where all have the same access.