The Azure Hybrid Benefit for SQL Server lets customers use their existing licenses to reduce the cost of Azure Virtual Machines service rates. Customers who have Software Assurance can use the Azure Hybrid Benefit to pay a reduced base rate for SQL Database vCore-based options (such as Managed Instance, vCore-based Single Database, and vCore-based Elastic Pool), SQL Server in Azure Virtual Machines, and SQL Server Integration Services (SSIS). You can apply this benefit even if the SKU is active. However, notice that the base rate will be applied from the time that you select it in the portal. No credit will be issued retroactively.
For more information, see Azure Hybrid Benefit and Azure Hybrid Benefit FAQ.