Is Dynamics AX the same as Dynamics 365 Finance and Operations?

Dynamics AX and Dynamics 365 Finance and Operations are not the same product, but they are directly related. Microsoft rebranded Dynamics AX as Dynamics 365 Finance and Operations in 2017 and later split it into two separate applications: Dynamics 365 Finance and Dynamics 365 Supply Chain Management. If you are running Dynamics AX today, you are running the predecessor of what has since become a cloud-native, continuously updated platform. The sections below walk through what changed, what stayed the same, and what upgrading actually looks like in practice.

What happened to Dynamics AX after Microsoft rebranded it?

Microsoft officially renamed Dynamics AX to Dynamics 365 Finance and Operations in 2017 as part of its broader push to unify its business applications under the Dynamics 365 brand. The product was not retired or replaced by something entirely new. Instead, Microsoft rebuilt and extended it on a cloud-first architecture, moved it to Azure, and shifted to a continuous update model rather than major version releases every few years.

Earlier versions of Dynamics AX, including AX 2009, AX 2012 R2, and AX 2012 R3, remained available as on-premises installations. Microsoft committed to supporting AX 2012 R3 until October 2023 under mainstream support, with extended support running through 2027. That means organisations still running older AX versions are now operating on borrowed time, with no new feature development and narrowing security update coverage.

The rebrand also marked a shift in how Microsoft positions the product. Dynamics AX was sold as a traditional on-premises ERP. Dynamics 365 Finance and Operations is sold as a cloud service with a subscription model, regular feature updates pushed automatically, and deep integration with other Microsoft products like Power BI, Azure DevOps, and the broader Power Platform.

How does Dynamics 365 Finance and Operations differ from Dynamics AX technically?

The most significant technical difference is the deployment model. Dynamics AX ran on-premises on servers your organisation owned or managed. Dynamics 365 Finance and Operations runs on Microsoft Azure as a cloud-hosted service, which changes how updates, customisations, and integrations work at a fundamental level.

In Dynamics AX, customisations were typically made directly to the application code, which made upgrades painful and expensive. Dynamics 365 Finance and Operations introduced the concept of extensions, a model where customisations sit on top of the core product rather than inside it. This makes applying Microsoft’s regular updates far less disruptive, but it also means older AX customisations cannot simply be carried over. They need to be rewritten as extensions during the migration.

Other meaningful technical differences include:

Update cadence: Dynamics 365 receives continuous updates from Microsoft, typically on a monthly and quarterly schedule. Dynamics AX received major version updates every few years.
Integration approach: Dynamics 365 uses APIs and connectors aligned with the Microsoft ecosystem. AX integrations were often built on older frameworks that do not translate directly.
User interface: The web-based interface in Dynamics 365 is substantially different from the Windows client used in older AX versions, which has implications for user training and adoption.
Licensing: Dynamics 365 uses a per-user subscription model. Dynamics AX used perpetual licensing with annual maintenance fees.

Can organisations still run Dynamics AX, or is migration mandatory?

Migration is not legally mandatory, but continuing to run Dynamics AX beyond its support window carries real operational risk. Microsoft ended mainstream support for AX 2012 R3 in October 2023. Extended support, which covers security patches but not new features or non-security fixes, runs through October 2027. After that date, organisations running AX 2012 R3 will receive no further updates from Microsoft.

Running unsupported software creates exposure on several fronts: security vulnerabilities go unpatched, integration with modern third-party tools becomes harder to maintain, and finding consultants with deep AX expertise becomes increasingly difficult as the talent pool shifts toward Dynamics 365. For organisations in regulated industries, running unsupported ERP software can also raise compliance questions.

In practice, most organisations that have not yet migrated are either in active planning, mid-project, or facing internal constraints that have delayed the move. The 2027 extended support deadline provides a concrete forcing function for those still on the fence.

What does upgrading from Dynamics AX to Dynamics 365 Finance actually involve?

Upgrading from Dynamics AX to Dynamics 365 Finance is a full ERP transformation project, not a technical patch or a simple version upgrade. Microsoft provides a data upgrade toolkit that helps move transactional and master data, but the broader project involves significantly more than data movement.

A typical migration from Dynamics AX to Dynamics 365 Finance covers:

As-Is analysis: Documenting current processes, customisations, integrations, and data structures in AX to understand exactly what needs to be replicated, redesigned, or retired.
To-Be design: Mapping business processes to standard Dynamics 365 functionality and identifying where extensions are needed to replace AX customisations.
Data migration: Extracting, cleansing, transforming, and loading data from AX into Dynamics 365, with rigorous testing to prevent data loss or integrity issues. This phase alone is one of the highest-risk parts of the project. Optinus approaches data migration management through detailed As-Is/To-Be analysis and testing procedures specifically designed to catch errors before they reach production.
Integration rebuild: Recreating connections to third-party systems using Dynamics 365’s API framework.
Testing: Full regression, user acceptance, and performance testing before go-live.
Cutover and go-live: The final switch from AX to Dynamics 365, typically executed over a planned downtime window with a detailed cutover plan to minimise operational disruption.
Hypercare: Post-go-live support to resolve issues quickly before they affect operations.

The scope and timeline vary depending on the complexity of your AX environment, the number of integrations, data volumes, and how much process redesign you want to include. Organisations that treat the migration as a pure technical lift-and-shift often end up replicating old inefficiencies in a new system. Those that use the migration as an opportunity to standardise and optimise processes tend to get more value out of the investment.

Should you choose Dynamics 365 Finance or Dynamics 365 Supply Chain Management?

Dynamics 365 Finance and Dynamics 365 Supply Chain Management are two separate applications that Microsoft split out from the original Dynamics 365 Finance and Operations product. The right choice depends on where your operational complexity sits, and many organisations license both.

Dynamics 365 Finance covers financial management, accounting, budgeting, project accounting, and compliance. It is the right choice for organisations whose primary need is robust financial control and reporting across multiple legal entities or geographies.

Dynamics 365 Supply Chain Management covers procurement, inventory, warehousing, manufacturing, and logistics. It is the right choice for organisations where operational complexity sits in the supply chain rather than the finance function.

In practice, most mid-to-large organisations coming from Dynamics AX used it across both finance and operations, which means they typically need both Dynamics 365 applications. The split does give you the option to phase your implementation, starting with one application before rolling out the other, which can reduce project risk and spread the change load across the organisation. That said, phasing also introduces integration complexity between the two applications during the interim period, which requires careful planning. You can explore our full range of services to see how program management and change management support can help structure that kind of phased rollout effectively.

How Optinus helps with Dynamics AX migrations

Moving from Dynamics AX to Dynamics 365 is a significant project, and the risk of getting it wrong is real. We work with organisations across the full migration journey, from the initial assessment of where you stand today through to go-live and post-go-live support. Here is what that looks like in practice:

Maturity assessment: Before any roadmap or budget is committed, we give you a clear baseline of your current AX environment, processes, and readiness for Dynamics 365.
Project and program management: Our consultants have hands-on experience from real ERP migrations at leading multinationals, not just frameworks on paper.
Data migration management: We run rigorous As-Is/To-Be analysis and testing to make sure your data arrives in Dynamics 365 clean, complete, and correct.
Cutover management: We plan and manage the go-live transition end-to-end, including hypercare and aftercare, so your operations keep running without interruption.
Change management: We help your teams actually adopt the new system, addressing both the technical and the human side of the transition.
Available on-site and remote: We work with organisations in the Netherlands, Belgium, and internationally, both on-site and remotely.

If you are planning a move away from Dynamics AX or trying to figure out where to start, get in touch with our team for a straightforward conversation about your situation. You can also learn more about what we do and how we approach ERP transformations from start to finish.

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