For customers who enroll in ESUs enabled by Azure Arc after the end of support dates (July 11, 2023 for SQL Server 2012 Year 2 and October 10, 2023 for Windows Server 2012/R2), they will be billed a one-time upfront charge for the months they missed after the end of support date, with billing coming in at the end of the month. For example, if a customer enrolls in January 2024, they will receive a one-time back-bill for October, November, and December 2023 during their first month.
This also applies if a customer intermittently deactivates ESUs. For example, if a customer enrolls in October 2023, unenrolls in November 2023 and re-enrolls in March 2024, the re-enrollment will trigger back-billing for December 2023, January 2024, and February 2024.