The Enterprise plan allows you to use Rails LTS for up to 20 applications.
Coherent services that are comprised of multiple Rails applications count as a single application for the purpose of Rails LTS licensing. For example, if distinct Rails applications are used for the frontend and backend of the same site, this counts as a single application. Also if you operate multiple staging and production instances for the same site, this counts as a single application.
Applications that are used to service distinct sites or clients are counted as separate applications.
An agency maintaining applications for several clients can use a single Rails LTS license, as long as the application limit is not exceeded.
If a client also has its own developers working on the application, a separate license is required.