For businesses that still run Dynamics NAV, delaying a move to Business Central now carries measurable costs and risks. Being aware that many NAV versions have already left mainstream support windows, and older releases no longer receive routine feature updates, is essential for moving forward.
Microsoft lifecycle documentation and vendor guidance show that reliance on unsupported software increases compliance issues and maintenance problems. Experts like Brookland Solutions, a certified Microsoft partner with over 20 years of experience working with UK companies, are specialists in guiding clients through these challenges.
Let’s look at five specific such challenges finance and IT teams face when upgrading from Dynamics NAV to D365 Business Central.
1. Data Migrations and Cleansing
Unclear or poorly managed datasets can create key challenges when implementing new systems. Old ledgers, inconsistent customer records, duplicate SKUs, and historic stock balances that don’t add up create unnecessary issues. Moving old, unused, and irrelevant data to Business Central is likely to only complicate the process.
Practical points to consider:
- Decide what truly needs migrating and move only the data that is still relevant to operations.
- Standardise master data before migration to improve consistency in customer names, addresses, VAT numbers, and product codes.
- Reconcile open balances and the trial balance before cutover.
- Use export, transform, and load scripts where possible rather than manual edits.
- Ensure VAT codes align with current HMRC requirements, especially if using Making Tax Digital cycles or special VAT schemes.
- A strong migration plan includes staging runs and reconciliation steps signed off by finance owners.
2. Custom Code and Extension
Many NAV installations have been heavily customised. Over time, local customisation and third-party add-ons have become essential for daily operations. However, Business Central is a fully modernised platform, and older C/AL code cannot be carried over without rework.
Options you will have to take into consideration include:
- Rebuilding the custom feature as an extension in AL
- Replacing the customisation with a modern, supported add-on
- Dropping the custom feature if it is no longer necessary
Rewriting takes time and budget, but blindly moving unsupported code will create technical debt. It is often beneficial to catalogue custom reports and modifications. Once these have been catalogued, they can then be scored by business value and rewritten to reflect the cost. Cataloguing and scoring these elements helps in understanding what processes are still effective for the company to be engaging with.
Conduct unit tests and user acceptance tests. Eventually, the sample transaction cycle will expose hidden assumptions. Keep in mind that, even with robust tests, there can still be unexpected factors that arise during the initial stages.
3. Integration With Systems
Most NAV environments depend on third-party integrations—such as payroll systems, CRM platforms, e-commerce stores, warehouse scanners, and banking feeds. Ensuring these continue to function during migration is essential.
Key steps to keep in mind:
- Inventory every integration, record direction, frequency, and data fields used
- Check whether the third party offers a Business Central connector
- Test the full flow end-to-end, not just the individual API
For example, payroll and HMRC submissions require precise posting formats. Any mapping error can disrupt payroll reconciliation and create extra work correcting HMRC submissions. A dry run before the first live payroll cycle helps identify issues early.
If you use e-commerce platforms such as Shopify or Magento, confirm that order statuses and stock levels remain accurate during cutover. Planning integration switchover windows is key to avoiding discrepancies.
4. User Adoption and Training
Business Central looks different from NAV; names may be different, workflows will be tweaked, and extra tabs may be added, and this can cause challenges for staff who are more familiar with older systems. Clear training and support are an important part of staff feeling confident in adopting new systems.
Make use of these tips:
- Run role-based training sessions with real examples
- Create a quick reference guide for the most frequent tasks staff need to complete
- Offer shadowing for a week after going live, so users can ask questions throughout the process
- Identify super users in each department and make them the champions of the new system, who can help model successful use for those who may be struggling
People in a smaller team often prefer hands-on learning. More flexible and personal training options can help to ease the transition and improve staff participation in these teams.
5. Licensing and Costing
The licensing model for Business Central is subscription-based; this means regular ongoing payments, unlike NAV. You will also need to plan for ongoing support contracts, cloud hosting costs, and third-party subscriptions.
Things that may need particular consideration include:
- Understanding the different licence types and which staff members need them
- Factoring recurring costs into year two and year three budgets, not just year one
- Budgeting for training and support during the first twelve months
In a subscription model, new updates may be pushed regularly. While new updates are often positive, it does mean that changes and updates need to be tested internally before reaching live users. This testing is important so the user experience is not negatively impacted.
In Conclusion
Upgrading NAV to Business Central is worthwhile, but it asks for proper planning, a change in the pricing module, users’ patience and some honest decisions.
It is important to carefully manage implementation steps and risks to enjoy the benefits of the trade to NAV from Business Central.
If you want to take the next step, connect with Microsoft partners who can help you through the migration. They keep projects running on schedule and reduce stress. They also identify which parts can retire and which ones must be preserved, so you can focus on the work that matters.
