ERP Data Migration Checklist: What to Move, Clean and Verify

Short answer: A sound ERP data migration moves three things and leaves the rest in an archive: master data (customers, vendors, items, the chart of accounts), open transactions (unpaid invoices, open orders), and opening balances. Closed history usually stays behind. The work is in cleaning and mapping the data first, running test loads, and reconciling each one against the old system until the numbers match. The checklist below takes you through it in order.

Last updated: 14 November 2026.

Data migration is where ERP projects quietly lose their schedule. The software can be configured on time and still not go live, because the data that has to arrive in it is not ready. This guide is a working checklist for finance and operations teams, whichever ERP you are moving to.

In this guide: Decide what moves · Clean the data · Map the data · Test loads · Reconcile · Cutover · Common mistakes · FAQ

1. Decide what moves and what stays

Data	Usual approach
Master data: customers, vendors, items, chart of accounts, employees	Move, after cleaning. Leave inactive records behind unless you have a reason to keep them.
Open transactions: unpaid invoices, open orders, unreconciled bank items	Move, at the amount still outstanding
Opening balances: trial balance, inventory quantities and values	Move, as of the cutover date
Closed transaction history	Usually archive. Move summary balances by period if you need comparative reporting.

ERP makers take the same line. NetSuite’s implementation guide says years of closed historical data typically do not need to migrate in full (NetSuite), and Microsoft’s Dynamics GP to Business Central tool moves summary history for the years you choose, with an optional snapshot of detail for reporting (Microsoft Learn). Before you decide, confirm how long your auditors and regulators need records kept, and where they will be able to see them.

2. Clean the data before you move it

• Merge duplicate customers, vendors and items.
• Mark records nobody uses as inactive, and decide whether they move at all.
• Close or write off old open items that will never be settled.
• Fix missing or inconsistent fields: tax IDs, payment terms, addresses, units of measure.
• Resolve partial payments and unapplied cash. Some migration tools move invoices at their full amount; Microsoft’s QuickBooks Online migration, for example, does not update partially paid amounts (Microsoft Learn).
• Name an owner for each data area in the business, not in IT. They decide what is right.

Cleaning in the old system is cheaper than cleaning during testing, when every fix has to be repeated in each load.

3. Map the data to the new system

• Chart of accounts first. Decide whether to keep the old structure or redesign it, and how departments, locations and projects will be tracked. Many ERPs use dimensions for what older systems handled with extra accounts or account segments.
• Field by field. For each record type, list every target field, its source, any transformation and its default value.
• Code lists. Payment terms, tax codes, currencies, units of measure and item categories need a one-to-one translation table.
• What has no equivalent. Note anything the new system does not support, and decide how to handle it before the first load.

4. Run test loads

1. Load master data first, then open transactions, then opening balances.
2. Use a full copy of real data, not a sample. Problems hide in the records nobody thought to include.
3. Log every error, fix the cause in the source or the mapping, and run the load again.
4. Time each load. The final run has to fit inside your cutover window.
5. Plan for at least two full rehearsals before the real cutover.

5. Reconcile every load

Check	Must match
Trial balance	Every account balance at the cutover date
Receivables and payables	Aged balances in total and by customer or vendor
Inventory	Quantities by item and location, and total value
Bank	Book balances and unreconciled items
Record counts	Number of customers, vendors, items and open documents

Have the business owner of each area sign off the reconciliation. If the numbers do not match in rehearsal, they will not match on go-live day.

6. Plan the cutover

• Choose a date just after a month or year-end close, so opening balances are clean.
• Freeze master data changes in the old system for the final days.
• Agree a written go or no-go checklist, and who makes the call.
• Keep the old system available read-only for reference and audit.
• Plan support for the first month-end close in the new system.

The mistakes that cost the most

• Moving everything. Years of closed history make every load slower and every reconciliation harder, for data few people will look at.
• Cleaning during testing. Each fix has to be repeated in every load, and the schedule slips.
• Leaving data to IT. Only the business can say which customer record is the right one.
• Too few rehearsals. A single test load rarely finds the problems a second one would.

Overruns are common enough to plan for. In Panorama Consulting’s 2026 report, more than a quarter of the organizations surveyed said their project was over budget, and almost a quarter said it was over schedule (Panorama Consulting, 2026). Our ERP cloud migration cost guide shows how to budget for data work, and our guide to choosing an ERP migration strategy covers how the route you choose changes what has to move.

Frequently asked questions

What data should be migrated to a new ERP?

Usually master data, open transactions and opening balances. Closed history is usually archived, with summary balances moved if you need comparisons by period.

How many test migrations should we run?

Enough to reconcile cleanly and time the final load. Plan for at least two full rehearsals with real data before cutover.

Who should own ERP data migration?

The business. IT and the implementation partner run the tools and loads, but finance and operations owners decide what is correct and sign off each reconciliation.

When is the best time to cut over to a new ERP?

Just after a month or year-end close, so the opening balances are clean, with the old system kept available read-only for reference.

Making the right call on your data migration

Move less, clean earlier, rehearse more. A migration that carries only what the business needs, cleaned and owned by the people who use it, reconciles faster and goes live calmer than one that tries to bring everything.

Appson Technologies runs full ERP implementations, from scoping and data migration through integrations, testing and go-live support. Tell us which system you are leaving, where you are going and your timeline, and we will tell you how we would approach the migration and what our proposal would cover. Discuss your ERP project.