# Windows Server 2016 ESU: cost and eligibility

> Windows Server 2016 ESU through Azure Arc costs $5.21 per core a month for Standard. What it covers, who can buy it, minimum cores and when it is worth it.

Source: https://wharfcloud.co.uk/guides/windows-server-2016-extended-security-updates · Last updated 21 October 2026 · WharfCloud

Published 21 October 2026. Reading time about 7 minutes.

## Short answer

Windows Server 2016 Extended Security Updates (ESU) give up to three more years of Critical and Important security fixes after extended support ends on **12 January 2027**, running through 2030. Through Azure Arc you can set them up from 3 August 2026 and billing starts on 13 January 2027. To buy them you need Software Assurance, or licences through a hosting provider's SPLA or a Server Subscription. Microsoft's published pay-as-you-go rate through Azure Arc is **$0.007132 per core per hour for Standard** (about $5.21 per core a month) and $0.041067 for Datacenter (about $29.98), effective 1 August 2026, with a minimum of 16 physical cores per server or 8 virtual cores per VM. ESU is a bridge for servers with a dated move plan, not a way to stay on 2016.

## What ESU covers, and what it does not

Microsoft's lifecycle FAQ describes ESU as a last resort, paid option for running a product past the end of support, and a temporary bridge while you move to a supported platform. For Windows Server 2016, Microsoft's Azure Arc documentation says ESU provides Critical and Important security updates for up to three years, through 2030.

Table: What you get with Windows Server 2016 ESU

| Included | Not included |
| --- | --- |
| Security updates rated Critical and Important | New features |
| Standard and Datacenter editions | Non-security fixes you request |
| Up to three years, through 2030 | General technical support beyond the security updates |

ESU does not extend the product's lifecycle. Your software vendors may still stop supporting their applications on Windows Server 2016 after January 2027, whether or not the server gets ESU. Pegasus, for example, says its Opera 3 support ends when Microsoft extended support ends.

## Who can buy it

Microsoft's Azure Arc documentation sets the rule for Windows Server 2016: to purchase ESU you need Software Assurance through a Volume Licensing programme (Enterprise Agreement, Enterprise Agreement Subscription, Server and Cloud Enrollment, Open Value and similar). If the servers are licensed through a hosting provider's SPLA or with a Server Subscription, Software Assurance is not required.

> **The catch for many small businesses** A lot of small firms bought Windows Server 2016 with the hardware (an OEM licence) or as a one-off retail or volume licence without Software Assurance. Under the rule above, those servers do not qualify for ESU through Volume Licensing. Check your licence paperwork, or ask whoever sold you the server, before you plan around ESU.

## How it is delivered and billed

1. **Connect the server to Azure Arc.** Install the Azure Connected Machine agent, version 1.62 or later for Windows Server 2016. The server stays where it is; Arc only connects it to the Azure portal for management and billing.
2. **Enrol from 3 August 2026.** Microsoft says you can configure Windows Server 2016 ESU in the Azure portal from 3 August 2026, through the portal or Azure Policy.
3. **Billing from 13 January 2027.** Arc-enabled ESU is billed monthly through your Azure subscription from 13 January 2027, with no product keys to activate.

Microsoft also sells ESU through Volume Licensing for some products, and partners can cover SPLA-licensed servers. Which route applies depends on how your Windows Server licence was bought.

## What it costs

Microsoft publishes the Azure Arc pay-as-you-go rates in its Azure Retail Prices API. For the meters "WS2016 Std 1C ESU" and "WS2016 DC 1C ESU", effective 1 August 2026 and checked on 21 October 2026:

Table: Windows Server 2016 ESU through Azure Arc, list prices per core (monthly figures use 730 hours)

| Edition | Per core per hour | Per core per month | Per core per month in GBP (API) |
| --- | --- | --- | --- |
| Standard | $0.007132 | about $5.21 | about £3.94 (£0.0054 an hour) |
| Datacenter | $0.041067 | about $29.98 | about £22.63 (£0.031 an hour) |

Microsoft's Arc licensing guidance sets minimums: licensing by physical cores needs at least 16 cores per machine, and licensing by virtual cores needs at least 8 virtual cores per virtual machine (Standard edition only). So the smallest bills are roughly **$41.65 a month for one virtual machine** (8 virtual cores, Standard) and **$83.30 a month for one physical server** (16 cores, Standard), before any discount or tax. A Standard licence covers up to two virtual machines on a host; Datacenter covers any number.

Microsoft's Azure Arc pricing page says the same list price applies wherever the server runs, including Azure, on-premises and other clouds, and however you buy it. The no-cost disaster recovery benefit and the Visual Studio dev/test benefit are not available for Windows Server 2016 ESU, according to the Arc licensing guidance.

Compare the quote with the alternative. Our [Windows Server 2016 migration plan](https://wharfcloud.co.uk/windows-server-2016-end-of-support) maps up to five servers to a destination for a fixed fee, and a [Managed Windows Server](https://wharfcloud.co.uk/managed-servers/windows) has a fixed monthly price with licence, patching and backups included.

## When ESU makes sense, and when it does not

Table: A quick way to decide per server

| Situation | ESU? |
| --- | --- |
| An application that cannot move before January 2027, with a dated plan to move it | Yes, for the shortest term that covers the plan |
| A file server, print server or domain controller | Usually no: these move easily to a supported release |
| A server with an OEM licence and no Software Assurance | Not available through Volume Licensing |
| A server that also runs SQL Server 2016 | Not enough on its own: SQL Server 2016 support already ended on 14 July 2026 |
| No plan at all, just hoping to delay | No. Three years ends in 2030 regardless |

If you hold Cyber Essentials, check with your certification body how it treats a server covered by ESU; our [Cyber Essentials guide](https://wharfcloud.co.uk/guides/cyber-essentials-unsupported-software) explains the rule on unsupported software.

## Frequently asked questions

### When does Windows Server 2016 extended support end?

On 12 January 2027, according to Microsoft's lifecycle page. After that date there are no free security updates.

### How long can I get Windows Server 2016 ESU?

Up to three years after the end of extended support, through 2030, according to Microsoft's Azure Arc documentation.

### How much does Windows Server 2016 ESU cost?

Through Azure Arc, Microsoft's list price is $0.007132 per core per hour for Standard (about $5.21 per core a month) and $0.041067 for Datacenter (about $29.98), effective 1 August 2026. With the minimum of 8 virtual cores per VM, one Standard VM costs about $41.65 a month.

### Do I need Software Assurance for ESU?

Yes, for servers licensed through Volume Licensing. Servers licensed through a hosting provider's SPLA or a Server Subscription do not need Software Assurance.

### Do I have to move the server to Azure?

No. Azure Arc connects a server that stays on your premises or with your host to the Azure portal for enrolment and billing. The workload does not move.

### Does ESU include technical support?

No. Microsoft's lifecycle FAQ says ESU covers the security updates only and does not provide technical support beyond the original support timeline.

## Sources

- [Microsoft Learn: Prepare to deliver Extended Security Updates for Windows Server (Azure Arc)](https://learn.microsoft.com/en-us/azure/azure-arc/servers/prepare-extended-security-updates)
- [Microsoft Learn: Lifecycle FAQ, Extended Security Updates](https://learn.microsoft.com/en-us/lifecycle/faq/extended-security-updates)
- [Microsoft Lifecycle: Windows Server 2016](https://learn.microsoft.com/en-us/lifecycle/products/windows-server-2016)
- [Microsoft Azure Retail Prices API: meters WS2016 Std 1C ESU and WS2016 DC 1C ESU (USD and GBP)](https://prices.azure.com/api/retail/prices?$filter=contains(meterName,%20%27WS2016%27))
- [Microsoft Azure: Azure Arc pricing](https://azure.microsoft.com/en-gb/pricing/details/azure-arc/core-control-plane/)
- [Microsoft Learn: License provisioning guidelines for Extended Security Updates (Azure Arc)](https://learn.microsoft.com/en-us/azure/azure-arc/servers/license-extended-security-updates)
- [Pegasus: Opera 3 Software Requirements Guide (June 2026), PDF](https://docs.pegasus.co.uk/Guides/Latest/Software_Requirements_Guide.pdf)

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