Dynamics AX to Business Central migration: routes, costs and what moves

If your company still runs Dynamics AX, you are running software that Microsoft stopped supporting years ago. The question is no longer whether to move, but where to: Dynamics 365 Finance & Operations, the direct successor of AX, or Business Central, Microsoft’s ERP for small and mid-sized businesses.

Many AX customers bought AX in the 2000s, when it was the natural choice for a growing company with ambitions. Some grew into it. Others now pay to maintain a system far bigger than their business needs. This guide is for the second group, and for anyone trying to work out which group they are in. It covers both routes, what actually moves in an AX to Business Central migration, what it costs and how long it takes.

Where Dynamics AX stands in 2026

Source: Microsoft Lifecycle pages for AX 2009 and AX 2012 R3.

Every AX installation is now out of extended support: no security updates, no regulatory updates, no fixes from Microsoft. The system won’t stop working tomorrow. It just gets riskier and more expensive to run every year, and, in our experience, people who know X++ are getting harder to find.

Two routes out of AX

Microsoft’s AX 2012 upgrade guide is candid about the first route. Upgrades are supported only from AX 2012 R2 and R3, not from AX 2012 RTM. Systems that use deprecated features such as virtual companies or data partitions “can’t currently be upgraded”. And Microsoft warns that AX 2012 upgrades “are complex” and that its tools are “a framework rather than a complete solution”. For AX 2009, Microsoft’s lifecycle page points to data migration guidance rather than an upgrade.

Business Central or Finance & Operations?

This is the decision that matters, and it is about your business, not your current software.

Business Central is usually the right target if:

• You have up to a few hundred users across a handful of legal entities
• Your processes are distribution, trading, services, projects or light-to-moderate manufacturing
• Much of your X++ code exists to work around AX rather than to run a process that makes you competitive
• Total cost of ownership matters. Business Central lists at €69.30 per user per month for Essentials and €95.30 for Premium, paid yearly (Microsoft pricing)

Finance & Operations is usually the right target if:

• You run many legal entities across countries with shared services
• You need advanced warehousing, process manufacturing or very high transaction volumes
• You want to keep your full AX 2012 history and data structures through Microsoft’s upgrade path
• Your customisations encode processes that no standard SME system will cover

If you are unsure, read our Business Central vs Finance & Operations comparison or our overview of Dynamics 365 Finance & Operations. We implement both, so we don’t need the answer to be Business Central.

Why AX can’t simply be “upgraded” to Business Central

Business Central descends from Dynamics NAV; Finance & Operations descends from AX. They are different codebases with different data models, so nothing in an AX database maps across automatically.

Business Central’s built-in cloud migration covers a defined list of sources. According to Microsoft’s migration documentation, these are Business Central on-premises, Dynamics NAV (via Business Central on-premises), Dynamics GP 2015 and later, Dynamics SL 2015 and later, and “any other SQL source using custom migrations”. AX is not on the list. A partner could build a custom migration for an AX database, but that is partner tooling, not a Microsoft product. The same page notes the source database must run on SQL Server 2016 or later with compatibility level 130 or higher, which older AX 2009 installations may not meet.

In practice, most AX to Business Central projects load data through Business Central’s configuration packages and Excel templates, or through a partner’s migration scripts.

What moves, and what stays behind

Financial dimensions deserve special care. AX 2012 users are used to rich dimension structures. Business Central supports as many dimensions as you need, with two global dimensions used as filters everywhere and up to eight shortcut dimensions on journal and document lines. Choose the global dimensions carefully: changing them later means updating every posted entry.

Legal entities become Business Central companies. If you report as a group, Business Central consolidates companies with different charts of accounts, fiscal years and currencies, even across environments. Eliminations are a manual step, so agree the group close process early.

What happens to your X++ customisations

Nothing converts automatically. Every modification is sorted into one of three buckets:

1. Retire. In our experience, a large share of old AX modifications cover things Business Central does as standard, or processes the business no longer runs.
2. Replace. A certified app from Microsoft’s marketplace covers the need, and its publisher maintains it through updates.
3. Rebuild. Genuinely differentiating logic is rewritten as an AL extension that adds to standard objects without editing the base application, so it survives Microsoft’s two major updates a year.

Integrations built on AX services are rebuilt against Business Central’s APIs. Our custom development team does this work. If you ran AX for retail, the natural Business Central equivalent is LS Central.

Timeline and cost

Partner fees are our typical ranges from the 2026 cost guide; your quote depends on scope.

A NAV customer moving to Business Central can often reuse data structures, which is why NAV migrations cost less. An AX customer can’t, so budget for a normal Business Central implementation with a heavier design and data phase.

What catches AX teams out

• Expecting AX behaviour. Business Central is simpler by design. Teams that try to rebuild every AX screen lose the benefit of moving.
• Underestimating the chart of accounts work. It is the foundation of every report. Give it senior finance time early.
• Keeping all history “just in case”. Migrate what you need to operate and compare; archive the rest where auditors can reach it.
• Leaving integrations to the end. Warehouses, banks, EDI partners and web shops all need testing before go-live.

Preparation checklist

• AX version and cumulative update level, SQL Server version, database size
• List of legal entities and how you consolidate today
• Current financial dimension structure and the reports that depend on it
• Inventory of X++ modifications, ISV add-ons and integrations
• Which history you must keep, for how long and where
• Your decision criteria: Business Central or Finance & Operations
• A target go-live that avoids your year-end close

Frequently asked questions

Is Dynamics AX still supported?

No. Extended support for AX 2012 R3, the last AX release, ended in January 2023, and for AX 2009 in April 2022. Microsoft no longer issues security updates, regulatory updates or fixes for any AX version.

Can AX be upgraded to Business Central?

No. Microsoft’s only upgrade path from AX goes to Dynamics 365 Finance & Operations, and only from AX 2012 R2 or R3. Moving to Business Central is a reimplementation plus a data migration of master data, opening balances and open documents.

Does Business Central’s cloud migration tool support AX?

No. The built-in cloud migration covers Business Central on-premises, Dynamics NAV via Business Central on-premises, Dynamics GP and Dynamics SL from 2015, and custom migrations for other SQL sources. For AX, data is usually loaded through configuration packages, Excel templates or partner migration scripts.

How long does an AX to Business Central migration take?

Typically 4–9 months, depending on the number of legal entities, modules, integrations and how much customisation needs rebuilding. The chart of accounts redesign and data cleansing usually take longer than teams expect.

How much does it cost?

It is priced like a new Business Central implementation: typically €18,000–40,000 in partner fees for a standard scope and €45,000–100,000+ for complex multi-entity projects, plus Business Central subscriptions from €69.30 per user per month for Essentials.

Do we lose our AX history?

No, but it usually stays out of Business Central. Most companies migrate open items and opening balances, sometimes with monthly net changes for comparison years, and keep posted history in a read-only AX archive or a reporting database.

Should we choose Business Central or Finance & Operations?

Business Central usually fits companies with up to a few hundred users, a handful of legal entities and standard distribution, services or light manufacturing processes. Finance & Operations fits many-entity, multi-country groups with complex supply chains, or companies that want to keep their full AX 2012 history through Microsoft’s upgrade path.

Still on AX and weighing your options? We implement both Business Central and Finance & Operations, so we can give you a straight recommendation for your size and processes. See our Business Central implementation service, our support and upgrades service, or get in touch.

Sources (checked 29 September 2026): Dynamics AX 2009 lifecycle · Dynamics AX 2012 R3 lifecycle · Upgrade from AX 2012 to finance and operations · Migrate on-premises data to Business Central online · Use Excel to import data · Dimensions · Consolidation · Developing extensions in AL · Business Central update cycles · Business Central pricing, eurozone