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Clean your data before you migrate to Business Central
Most migration projects slip not because the code was hard, but because the data was dirty. Twenty years of NAV use leaves behind duplicate customers, broken document links and dimension entries that point nowhere — and all of it has to land cleanly in Business Central. This is the companion to our upgrade checklist: that one tells you what decides the cost; this one goes deep on the single factor most likely to blow the timeline.
Start with a trial migration against a backup
Before you clean anything, run a trial migration against a recent database backup. It is the cheapest diagnostic you can buy.
A dry run surfaces the real problems — the records that fail validation, the links that break, the entries that refuse to balance — long before they can derail a go-live weekend. You fix against the copy, repeat, and only schedule the real cutover once the trial runs clean.
Why it matters: every defect you find against a backup is a defect you do not discover at two in the morning during cutover, when the cost of fixing it is ten times higher and the whole business is waiting.
Duplicate and merged customers and vendors
Years of manual entry produce the same customer under three spellings, vendors merged by hand, and master records no one dares delete because something still posts against them.
- Deduplicate customers and vendors before migration, not after.
- Decide which record survives and reassign open entries and history to it.
- Resist merging in the new system later — it is far harder once posting has resumed.
Why it matters: clean master data is the foundation every report, statement and reminder is built on. Duplicates fragment a customer’s balance and quietly corrupt the numbers your finance team trusts.
Broken document links and orphaned dimensions
Posted documents whose links no longer resolve, and dimension entries pointing to dimension values that were deleted long ago, are classic NAV residue. They migrate without complaint and then break reporting on the other side.
- Reconcile posted documents against their ledger entries.
- Find dimension entries referencing values that no longer exist and decide whether to repair or retire them.
- Confirm every open entry that must carry a dimension actually does.
Why it matters: dimensions drive your analytical reporting in Business Central. Orphaned or missing dimension data means month-end reports that do not tie out — and a finance team that stops trusting the system in its first week.
Obsolete items and stale master data
Most catalogues are full of items not sold in years, blocked-but-not-archived records, and price lists no one maintains. Migrating them costs testing time and clutters the new environment for everyone.
- Flag and exclude genuinely dead items rather than carrying them across.
- Archive what you may need for history but will never transact against again.
- Treat the migration as the one clean break you will get for a decade.
Why it matters: a lean master data set makes every search, every lookup and every user faster from day one — and a smaller dataset is quicker to migrate and test.
Open-entry accuracy and who owns the cleanup
Open customer, vendor and bank entries must reconcile to the penny before cutover, because they become opening balances you will live with.
And cleanup is a business responsibility, not a technical one. Your partner can find the defects and build the tools; only the people who know the customers, the items and the history can decide which record is correct.
- Assign a named data owner per area — receivables, payables, inventory.
- Reconcile open entries to the general ledger before the final migration.
- Lock the decisions — survivor records, what to archive, what to drop — before cutover, not during it.
Why it matters: opening balances are the first thing an auditor checks and the hardest thing to correct after go-live. Getting them right before cutover is far cheaper than reversing them after.
Planning a move to Business Central and want to know how clean your data really is? Tell us your story and we will run a trial migration and give you an honest, free assessment.