Data Migration & Opening Balances

Why data migration matters

The migration sequence

Order matters. Priya always follows this sequence:

Step	What to Migrate	Why This Order
1	Setup data — posting groups, number series, dimensions, payment terms	Everything else references these
2	Chart of accounts — GL accounts with categories	Posting groups map to GL accounts
3	Master data — customers, vendors, items, fixed assets	These reference posting groups and dimensions
4	Opening balances — GL balances, customer/vendor balances, item quantities	Must match the trial balance from the old system
5	Open documents — outstanding purchase orders, sales orders	Carry forward incomplete transactions

💡 The golden rule of migration order

Setup before master data. Master data before transactions.

If you try to import customers before posting groups exist, every customer will fail validation (no posting group to assign). If you try to import opening balances before the chart of accounts exists, the journal lines have nowhere to post.

Priya’s shortcut: use the configuration worksheet to order tables by dependency. Business Central even suggests the correct sequence when you add tables to a package.

Migration approaches

Migration methods compared

Method	Best For	Data Volume	Complexity
Configuration packages	Full implementations, repeatable migrations	Large (thousands of records)	Medium — requires Excel skills
Data migration wizards	QuickBooks, Dynamics GP migrations	Medium	Low — wizard-guided
Edit in Excel	Small updates, manual corrections	Small (hundreds)	Low
Manual entry	Very small datasets, corrections	Tiny	High effort per record
Opening balance journals	GL/sub-ledger starting balances	Medium	Medium — must balance

Creating opening balances

Opening balances establish where the old system left off and the new system picks up. This is typically done on the go-live date — the first day of a new fiscal period.

GL opening balances

Olivia needs to bring Coastal Traders’ trial balance into Business Central. She uses a general journal:

1. Open General Journals (Tell Me > “General Journals”)
2. Select or create a journal batch
3. For each GL account, enter a line:
   • Posting Date = go-live date (typically the first day of the new fiscal period)
   • Document Type = leave blank
   • Account Type = G/L Account
   • Account No. = the GL account number
   • Amount = the balance (positive for debit, negative for credit)
4. The balancing account is usually a temporary Opening Balance equity account
5. Post the journal

💡 Exam tip: Opening balance posting date

The posting date for opening balances should be the last day of the previous period or the first day of the new period. This ensures:

• The old period closes cleanly
• The new period starts with correct balances
• Financial reports don’t mix old-system and new-system transactions in the same period

Most implementations use the day before go-live as the posting date for opening balances.

Customer and vendor opening balances

For sub-ledger balances (what customers owe you, what you owe vendors), Olivia creates separate journal entries:

Ledger	Account Type	What to Include
Customer	Customer	Outstanding invoices — one line per open invoice with invoice number and due date
Vendor	Vendor	Outstanding bills — one line per open bill with vendor invoice number and due date
Bank	Bank Account	Current bank balances

Critical: Customer and vendor opening balances must be entered as individual open entries (one per invoice), not lump sums. This ensures:

• Aging reports are accurate from day one
• Payment application works correctly
• The cash receipt and payment journals can match specific invoices

Item opening balances

For inventory, Raj uses an item journal to establish starting quantities:

1. Open Item Journals (Tell Me > “Item Journals”)
2. Enter one line per item per location:
   • Item No. = the item
   • Location Code = the warehouse location
   • Quantity = on-hand quantity
   • Unit Cost = the item’s current cost
3. Post the journal — this creates item ledger entries and value entries

Migrating data within Business Central

The exam also covers migrating data between companies within the same environment. This uses the same configuration package approach:

1. Export a package from the source company
2. Switch to the target company
3. Import and apply the package

Common scenario: a holding company creates a standard setup, then replicates it to subsidiary companies.

Question

What is the correct order for data migration?

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Answer

Setup data (posting groups, number series, dimensions) → Chart of accounts → Master data (customers, vendors, items) → Opening balances → Open documents. Setup before master data, master data before transactions.

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Question

Why should customer/vendor opening balances be entered per invoice, not as lump sums?

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Answer

Individual entries ensure accurate aging reports from day one and allow the payment application process to match payments to specific invoices. Lump sums break aging and payment matching.

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Question

What posting date should opening balances use?

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Answer

Typically the last day of the previous period or the first day of the new period. This cleanly separates old-system and new-system transactions and ensures financial reports are accurate.

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Knowledge check

Knowledge Check

Priya is migrating Coastal Traders from QuickBooks to Business Central. She has the chart of accounts ready, but customer posting groups haven't been created yet. She tries to import the customer list via a configuration package. What happens?

ACustomers import successfully — posting groups are optionalBThe import succeeds but customers get the default posting group automaticallyCThe validation step shows errors because posting groups are required and don't exist yetDBusiness Central creates the missing posting groups automatically during import

Check Answer

Knowledge Check

Olivia is entering customer opening balances for Coastal Traders. She has 150 customers with a total of 340 outstanding invoices. How should she enter the opening balances?

AOne journal line per customer with the total outstanding amountBOne journal line per outstanding invoice with the invoice number and due dateCOne journal line for the total accounts receivable balance posted to the AR control accountDImport all 340 invoices as sales invoices, then post them

Check Answer

Knowledge Check

Priya is migrating item data for Summit Distribution. She exported items from the old system into a configuration package, imported it into Business Central, and sees 12 validation errors. What should she do next?

AApply the package — the 12 errors will be skipped and she can fix them laterBReview the error log, fix the issues in the Excel file, re-import, and validate againCDelete all items and start the import from scratchDApply the package, then manually fix the 12 items in Business Central

Check Answer

🎬 Video coming soon

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Next up: Your company is created and data is loaded. Now let’s set up users, profiles, and security to control who can do what.