Blog
NAV to Business Central: an upgrade checklist
Every NAV to Business Central upgrade quote you receive is an answer to the same set of questions. This is the checklist we run before giving a number; use it to understand your own system before you talk to any partner, including us.
1. Which NAV version are you starting from?
The starting version decides the technical route. From NAV 2017 or 2018 the conversion to Business Central is fairly direct. From 2013 to 2016, code and data pass through intermediate platforms on the way. NAV 2009 or earlier means a multi-hop upgrade across several versions, and it usually means the original developers are long gone.
How to check: open Help → About in the classic or Windows client, and note both the version and the build. The build matters because localised databases (including Lithuanian ones) sometimes sit on non-standard builds that change the path.
We built our own upgrade tooling largely because of the older versions; it has carried systems from as far back as NAV 2009, including databases with thousands of objects.
2. How many custom objects do you really have?
Split your object list three ways: untouched standard, modified standard, and fully custom. Modified standard objects are the expensive category, because each modification must be re-expressed as an AL extension or replaced by functionality Business Central now ships out of the box.
How to check: in the Object Designer, filter each object type on Modified = Yes and export the list. Count the modified standard objects separately from your 50000-range custom ones. Two systems with the same total can differ wildly in cost depending on that split.
What actually happens to each category during conversion is its own topic; we cover it in From C/AL to AL: what a conversion actually involves.
3. Which customisations does standard BC now cover?
NAV solutions accumulated custom code for things Business Central now does natively: approval workflows, email from documents, bank reconciliation imports, late payment prediction. Every such customisation you drop instead of converting saves money now and keeps saving it in every future maintenance hour.
How to check: for each customisation, ask what business problem it solved, then ask a partner (or the release notes) whether standard BC solves it today. The answer changes every release, in your favour.
4. What do your ISV add-ons do in BC?
Payroll, EDI, barcoding, industry verticals: most NAV systems carry at least one third-party add-on, and it is often the single biggest unknown in a quote. Each add-on has one of three futures: the vendor offers an AppSource successor you subscribe to, the functionality is now covered by standard BC, or there is no successor and a replacement has to be scoped.
How to check: list every add-on with its vendor and version, then check AppSource and the vendor’s roadmap. Do this early; an add-on with no successor can reshape the whole project.
5. How do your integrations connect?
Anything that reads the SQL database directly, connects over ODBC, or drops files into a shared folder will not survive the move to SaaS. Those integrations must be re-plumbed through APIs and webhooks, which is a known, plannable cost when found in the audit and a crisis when found during cutover.
How to check: inventory every system that talks to NAV (webshop, warehouse, payroll, bank, BI) and write down how it connects, not just that it does. The options on the BC side are covered in our integration patterns post.
6. How dirty is your data?
Posted documents with broken links, orphaned dimension entries, customers merged by hand over the years. Data quality, not code volume, is the most common cause of timeline overruns.
How to check: run a trial migration against a database backup. It is the cheapest diagnostic available and surfaces the real problems months before go-live. The cleanup itself has its own checklist.
7. SaaS or On-Premise?
Business Central runs in both. SaaS removes infrastructure work and delivers two major updates a year automatically; On-Premise remains valid when regulation or heavy integrations demand it. Decide before the upgrade starts — it changes the migration path.
8. What happens to your licences?
NAV licences were typically perpetual and concurrent: you bought them once and users shared a pool. Business Central SaaS is a named-user subscription, so twenty concurrent NAV users may translate into thirty or more named users, each with their own monthly cost.
How to check: count the distinct people who sign in, not the sessions. Then sort them into full users and light users (the cheaper Team Member licence), and ask about transition offers for existing NAV customers before assuming list price. Budget the running cost alongside the project cost.
9. Who supports it afterwards?
An upgrade is not done at go-live. The first month-end close, the first VAT declaration, the first year-end: plan named support for these milestones into the project, not as an afterthought.
Considering an upgrade? We will run this checklist against your system and put a real number on it — tell us your story.