To Implement HA strategy require licensing Cost

In addition, the number of cores needing a license is the max of the number of hardware cores (or vm cores if vm hosted) or 4. If you have SA then passive servers are free. Passive means no read access on the failover servers. If no SA then the failover servers each need a license and allow read access.

This is a technical forum and not a good place to ask commercial questions. It is better to direct such questions to your local Microsoft representative or a partner. I do see that Q&A Assist AI service has given you answer, but I cannot vouch for its correctness.

What I do recommend is that you get Software Assurance. This permits you to have a passive node (extra), and good benefits when it's time to upgrade.

For SQL Server 2025 Enterprise Edition with Always On high availability (HA), licensing is per core, and Always On features are included in Enterprise Edition at no extra SQL Server feature cost. The total cost depends on:

1. How many cores must be licensed
2. Whether Software Assurance (SA) and/or Azure benefits are used
3. Whether the replicas are active or passive, and where they run (on-premises vs Azure)

1. Enterprise Edition core licensing and indicative pricing

SQL Server Enterprise Edition is licensed per 2‑core pack.

From the provided pricing examples:

• Enterprise Edition (2‑core pack): approximately US$15,000+ (exact price depends on region, reseller, and agreement)
• With Software Assurance, add roughly 25–30% on top of the license price for the SA term (for example, 2 years) if buying perpetual licenses.

So, for planning purposes only (non-binding, approximate):

• 2 cores Enterprise: ~US$15,000+ (license only)
• 4 cores Enterprise: ~2 × 2‑core packs ≈ US$30,000+
• 8 cores Enterprise: ~4 × 2‑core packs ≈ US$60,000+

For precise commercial pricing, a Microsoft licensing partner or reseller must be consulted.

2. Always On HA features and edition

For SQL Server 2025:

• Always On availability groups (full AGs) are supported in Enterprise only.
• Basic availability groups are supported in Standard only.

Since the plan is Enterprise Edition with Always On HA, the correct edition for full AG capabilities is Enterprise.

Relevant HA features in Enterprise include:

• Always On availability groups
• Contained availability groups
• Distributed availability groups
• Automatic read/write connection rerouting
• Advanced online operations (online index operations, online schema change, etc.)

These features are part of Enterprise Edition and do not have separate feature surcharges; the cost impact is through the Enterprise per‑core licensing.

3. HA/DR licensing considerations (on-premises vs Azure)

If HA is implemented on Azure SQL VMs instead of purely on-premises, there are additional cost-optimization options:

• With Software Assurance, it is possible to implement HA/DR with SQL Server on Azure VMs without extra SQL Server licensing cost for passive DR instances. This applies when using SQL Server licenses with SA and Azure Hybrid Benefit.
• There is also a free DR replica in Azure benefit: with SA, a passive DR replica in Azure can be configured without additional SQL Server license cost for that passive node. When all replicas are in Azure and using pay‑as‑you‑go licensing, customers can also be entitled to license‑free passive replicas when configured as HA/DR.

If using pay‑as‑you‑go SQL Server on Azure VMs instead of bringing licenses:

• The SQL Server license cost is included in the per‑second VM price and depends on the number of vCPUs and the edition (Web, Standard, Enterprise).
• This model is often better for workloads with unknown lifetime or variable scale.

4. Developer and lightweight scenarios

For non-production environments (dev/test, PoC) related to the HA design:

• SQL Server Developer Edition is free and has all Enterprise features, including Always On, but is not allowed for production.
• SQL Server Express Edition is also free and allowed for lightweight production workloads, but many Enterprise-level HA/DR features are not available, so it is not suitable for an Enterprise Always On design.

5. Recommended next steps to get a complete cost picture

To obtain a complete and accurate licensing cost for the Always On HA deployment:

1. Determine the total number of physical or virtual cores that will run production Enterprise instances (including HA replicas that are active/primary or readable secondaries).
2. Decide whether to:
   • Purchase perpetual Enterprise core licenses with SA, or
   • Use subscription/CSP or pay‑as‑you‑go models (for example, Azure VMs), or
   • Use Azure Hybrid Benefit if existing licenses with SA are available.
3. Engage a Microsoft licensing partner or reseller with the core counts and HA topology (number of replicas, which are active vs passive, on-prem vs Azure) to get exact pricing for:
   • Enterprise Edition per 2‑core pack
   • Software Assurance add‑on
   • Any Azure VM/pay‑as‑you‑go costs if applicable.

References:

• Manage licensing and billing of SQL Server enabled by Azure Arc
• Pricing guidance for SQL Server on Azure VMs
• Migrate SQL Server workloads (FAQ)
• Editions and supported features of SQL Server 2025
• Business continuity and HADR for SQL Server on Azure VMs
• SQL EE + SA cost of 4 core and 8 core - Microsoft Q&A
• SQL Server on Windows with Reporting Services (SSRS) Pricing - Microsoft Q&A
• what is the price for sql server license enterprise edition? - Microsoft Q&A