2025 is not a year for half measures. Since v26 (2025 Wave 1), a clear, staged path applies to many scenarios: for the cloud migration, your on-prem solution has to be brought to at least v25; v26 is also a stepping-stone release, which means direct jumps across several major versions are restricted. That affects budget, downtime and tool selection – noticeably so.

These are your options for the upgrade.

1) Greenfield

Only important master data (customers, vendors, items, open balances where applicable) plus new processes/customizing in Business Central.

Advantages: Lean, fast, less legacy baggage.

Disadvantages: History remains in the legacy system/archive; additional effort for reporting across the old and the new system.

2) Complete data transfer

The full history (master data and transaction data) moves to Business Central.

Advantages: One system, full ability to provide information.

Disadvantages: Technically more complex, larger data volume and therefore typically longer switchover windows, more testing.

The options at a glance

Option

Type / approach

Suitable for

Parallel operation with Live-Sync

Go-live downtime (for technical reasons)

Notes

Configuration packages (RapidStart)

Data transfer via Excel/package; built into BC

“Greenfield” (master data, basic configuration)

No

Importing larger data volumes can block the system; not suitable for live production

For initial setup; XMLports are the better choice for bulk imports; since 2024/25 BLOB and multi-line text are possible via Base64

DataMigrate Pro (IO Integrated)

Direct migration including bidirectional synchronization, delta loads

“Greenfield” and complete transfer

Yes – NAV & BC in parallel, Live-Sync

Very low; you choose the switchover time

Supports very old NAV versions; target cloud or on-prem; no jump versions required (vendor information)

Third-party providers (typically your Dynamics NAV & Navision partner)

Project service on the Microsoft standard path (C/AL→AL, upgrade toolkit, data upgrade); clean start including data migration

Clean start or complete transfer

No (no Live-Sync)

Yes – the data upgrade requires a maintenance window; one-way street

Test and production data migration; custom tables optional

Note: why is the standard path a “one-way street”? During the Microsoft data upgrade all clients are disconnected; after a successful data upgrade, renewed replication from the old version is not permitted (risk of data corruption). This is a technical constraint and applies regardless of which service provider carries out the upgrade.

Strengths & weaknesses in detail

Configuration packages (formerly "RapidStart")

Pros:

  • Built in, cost-effective, fast for master data (customers, vendors, items, basic G/L setup).
  • Since 2024/25: BLOB and multi-line text can be processed through a package (Base64).

Cons:

  • Not intended for existing production companies; large imports can block usage - use XMLports for bulk imports.
  • No Live-Sync, no history conversion (import only), testing/troubleshooting often manual.
  • Transfer of entries or of posted / unposted documents (e.g. invoices) is not possible
  • Very slow with large data volumes
  • Configuration packages have to be imported in the correct order, otherwise validation errors occur (with links between tables)

Conclusion: ideal for a “greenfield” start. Unsuitable for a complete data transfer (including posted entries and documents), or at least laborious and slow.

DataMigrate Pro (IO Integrated)

Pros:

  • Direct migration from very old Navision/NAV versions without "jump versions"
  • Bidirectional live synchronization (NAV↔BC), delta loads, parallel operation - resulting in minimal / no downtime and a Cutover you can plan.
  • Target cloud or on-prem; suitable for greenfield (subset) and for complete transfer.

Cons:

  • Extensive features that mostly work via a command line tool. This may require a short introduction to their use.

Conclusion: technically attractive if downtime is to be minimized and the legacy history is to be carried over in full.

Service provider on the Microsoft standard path

Pros:

  • Use of the standard upgrade path

Cons:

  • Cutover‑downtime is inherent to the system: during the data upgrade all connections are cut; after that replication is no longer permitted - a one-way street.
  • For BC Online / SaaS the OnPrem system must be at least v25 -> additional intermediate steps may be required.
  • Most expensive solution (usually between 50.000 and 150.000 EUR)

Conclusion: if a long downtime and high costs are not a problem, then this approach is an acceptable solution.

Specifics you should not ignore

  • Cloud migration only from v25 - before the move to the cloud, an update to v25 is required; v26 acts as a stepping‑stone release.
  • Data upgrade = maintenance window - regardless of the service provider, clients are disconnected until the step is complete; going back with renewed replication is not supported. A classic one-way street. That is no longer up to date.
  • Configuration packages are not a bulk ETL tool - for bulk imports in production, Microsoft advises against packages (performance risk) and points to XMLports instead.

Decision matrix (short and to the point)

Risks & pitfalls that hurt

  • Downtime underestimated: in a standard upgrade the data upgrade step is a hard cut; if you have to plan to the minute, you need clean advance tests or you choose Live-Sync.
  • Data quality: duplicates, wrong number series, faulty dimensions blow up in the new system. Plan data cleansing early.
  • Add‑ons/customizing: C/AL‑customizations must be transferred cleanly to AL/Extensions; the effort depends on the scope of the legacy system.
  • Configuration packages are overestimated: good for master data - not as a history-capable ETL or during ongoing production.

Checklist: how to make the right decision (in 30 minutes)

  • Does BC have to be online? If so and you are on < v25, plan for an intermediate step to v25 (the older the source version, the more intermediate steps are needed) or check direct migration/Live-Sync.
  • How much history do you need in BC? Master data only -> RapidStart; full history -> DataMigrate Pro or a standard upgrade with a Go-live window and long downtimes.
  • Downtime tolerance: none / hardly any tolerance -> Livesync; weekend Cutover and high costs acceptable -> standard upgrade.
  • NAV version very old? Direct migration without intermediate versions saves time/complexity.
  • Budget/responsibility model: technically driven & migration-focused -> DataMigrate Pro.

See also the official documentation from Microsoft.

Conclusion

  • Greenfield: set up configuration packages for master data and processes from scratch. Fast and cost-effective - but not for bulk imports in live operation.
  • Complete data transfer: when downtime is critical and costs are to be kept low, or when the source version is very old: DataMigrate Pro (parallel operation, Live-Sync).
  • Classic Cutover window acceptable and fixed price/standard important: Business Central partner (such as IO Integrated) - accept that the data upgrade is a one-way street and that the costs can escalate.
Sascha Marquardt
About the author

Sascha Marquardt

Responsible for the partner programme, the licensing business and commercial project delivery.