Overview
This post lists the 10 most common Business Central implementation mistakes and shows how to avoid each one. It reflects how UK SMEs run projects in 2026, including cloud updates, data migration and AI.
Key Takeaways
- Most failures start before kick-off, with vague goals, weak data and an unclear scope.
- Clean data and role-based training matter as much as configuration.
- In Business Central online, customisation happens through extensions, so keep it small and documented.
- Test in a sandbox with real scenarios, and retest after every major update.
- Budget for contingency, and control scope with a formal change process.
- Support does not end at go-live, so agree support terms and KPIs before you start.
How Business Central Implementation Mistakes Have Changed since 2025
The original post gave a short checklist of the same ten mistakes. Those mistakes still hold, but the detail has moved on.
Business Central online now updates twice a year, so testing never really stops. Customisation happens through extensions, which means every change carries a maintenance cost. AI has also raised the stakes on data, because agents rely on clean contacts and item records.
We have rewritten each section with those points in mind. Our guide to preparing for a Business Central implementation covers the groundwork in more detail.
1. Poor Planning and Unclear Objectives
The mistake: Teams often start configuring before they agree what success looks like. That leads to mismatched expectations, rework and wasted budget.
How to avoid it:
- Write down three to five business objectives, such as a faster month-end or accurate stock.
- Run a needs assessment with every department that will use the system.
- Agree a realistic timeline with milestones and named owners.
Our implementation approach begins with an Inspect phase for this reason. We agree the solution and get it signed off before any build work starts.
2. Ignoring Data Migration and Clean-Up
The mistake: Moving outdated, duplicate or incorrect data into Business Central causes errors from day one.
How to avoid it:
- Audit and clean your existing data before you migrate anything.
- Map fields carefully between the old and new systems.
- Run test migrations, and reconcile ledgers and stock balances before go-live.
If you are moving from Dynamics NAV, our Migrate from NAV page explains your options.
3. Underestimating Training and Change Management
The mistake: Assuming staff will pick the system up as they go leads to low adoption and spreadsheet workarounds.
How to avoid it:
- Provide role-specific training for each department.
- Phase the training from basic tasks to advanced ones, so people build confidence.
- Name super-users who can help colleagues after go-live.
Copilot can help new starters too. Our guide to Chat with Copilot shows how users can ask Business Central how to complete a task.
4. Choosing the Wrong Implementation Partner
The mistake: Selecting a partner on price alone often costs more later, through poor configuration and slow support.
How to avoid it:
- Look for a Microsoft Solutions Partner with experience in your industry.
- Ask for client references from businesses like yours.
- Check who will actually do the work, and whether the price includes support after go-live.
Our step-by-step guide to choosing an ERP helps you shortlist, and you can read why Business Central users choose Tecvia.
5. Over-Customising the System
The mistake: Business Central online does not let you change the base application. Customisation happens through extensions, so every extra adds cost at each update.
How to avoid it:
- Use standard features first, because they update automatically with the product.
- Check for an existing AppSource app before you commission custom code.
- Document every extension, and test it after each major update.
Our Business Central features page shows how much the standard system already covers.
6. Skipping Testing before Go-Live
The mistake: Going live without proper testing disrupts orders, invoices and stock. Integrations cause many of the surprises.
How to avoid it:
- Run user acceptance testing with real business scenarios.
- Test every integration, such as your online shop, bank feeds and trading partners.
- Use a sandbox environment for testing, not your live company.
- Pilot the system with a small group before everyone switches.
Testing continues after go-live. Microsoft releases major updates to Business Central online twice a year, so retest your extensions and integrations each time.
7. Neglecting Post-Implementation Support
The mistake: Treating go-live as the finish line leaves users stuck when questions arise.
How to avoid it:
- Agree support terms and response times before go-live.
- Schedule regular system reviews to catch problems early.
- Train your team on new features as Microsoft releases them.
Our support service prices one level of support per user, with a first response within an hour for business critical issues.
8. Forcing Old Processes into the New System
The mistake: Copying outdated processes into Business Central recreates the same problems in a new interface.
How to avoid it:
- Map your current processes, and remove steps that add no value.
- Use the standard workflows and approvals where they fit.
- Accept some change, because that is where the efficiency gain comes from.
Industry setup matters here. See how we configure Business Central for Manufacturing and Engineering and Distribution and Wholesale businesses.
9. Inadequate Budgeting and Scope Creep
The mistake: Costs rise when teams underestimate data, integration and training work, or accept changes informally.
How to avoid it:
- Set a clear budget with a contingency for unexpected costs.
- Freeze the scope after design sign-off.
- Log every new request through a change process that shows the cost and time impact.
Consider an illustrative calculation. If your project budget is £100,000, a 15% contingency reserves £15,000 for surprises. Our pricing page shows current Business Central licence costs.
10. Failing to Define KPIs and Measure Success
The mistake: Without measures, you cannot show that the project paid off.
How to avoid it:
- Set measurable KPIs, such as days to close the month or stock accuracy.
- Use Business Central reports and Power BI to track them.
- Review results against your targets every quarter.
Our Power BI for Business Central page explains how to build dashboards for these measures.
What This Means for Your Business
A successful Business Central implementation gives equal weight to planning, data, people and support. Most of the mistakes above are cheap to prevent early and expensive to fix late.
Use the list as a checklist before you sign a contract. If you cannot answer one of the ten, raise it with your partner now. Our post on on-premise vs cloud ERP can help you decide the deployment model first.
Get Help with Your Business Central Implementation
Tecvia helps UK SMEs plan, build and support Business Central projects. Get in touch with Tecvia to book a free consultation on your project.
Already live and unhappy with your current partner? Your Business Central tenant belongs to you, so you can switch your support partner without a rebuild. You can also read how our implementation approach works.
FAQs
Most problems trace back to planning, data and people. Vague objectives, poor data quality, weak training and informal scope changes cause more trouble than the software does. Address these early and your project risk falls sharply.
It depends on your number of users, how much data you migrate and how many systems you connect. A good partner gives you a timeline after the design phase, before the build starts. Be wary of a firm date at the start.
Microsoft prices licences per user per month. What you spend beyond that depends on configuration, data migration and integrations. Check our pricing page and ask for a written outline with costs and timescales.
Poor planning with unclear objectives is the most common. Teams that skip it find that every later decision becomes harder. Agree measurable goals and get the solution signed off before the build begins.
Yes, but in Business Central online you do it through extensions, not by changing the base application. Use standard features first and check AppSource before you commission custom code. Document each extension and test it after every major update.
Remove duplicates, archive inactive customers, suppliers and items, and correct missing fields. Then map each field to its new home and run test migrations. Reconcile balances after every test so you trust the result.
Agree support terms and response times before you go live. You also need regular system reviews and training when Microsoft releases new features. Choose a partner who absorbs small changes rather than quoting for every tweak.
Yes. Your Business Central tenant belongs to you, so changing partner changes who supports and develops it, not the system itself. Our partner transfer page explains how switching works.
