Choose the conversion date and migration scope
The conversion date is the date of the opening balances in Xero. Choose a date that supports a clean cut-off, often the start of a GST period, month or financial year. Balance the convenience of a simple opening position against the reporting value of historical detail. The scope may include opening balances only, comparative monthly balances, outstanding invoices and bills, contacts, fixed assets and selected transaction history.
Document what will not be migrated. Retain exports and reports from the old system so earlier records remain accessible. Confirm the legal entity, base currency, balance date, GST settings and reporting requirements before configuring Xero.
Clean the source data before import
A migration should not carry every old error into a new platform. Reconcile bank accounts, receivables, payables, GST, payroll liabilities, loans, fixed assets and equity in the source system. Review duplicate contacts, inactive accounts, suspense balances, old credits and negative invoices. Resolve unexplained historical adjustment balances where possible.
Agree the final source trial balance and save it as the control document. If the source records are unreliable, create a separate clean-up schedule and identify amounts that require professional judgement. Do not force the conversion to balance through an unexplained account.
Design the Xero chart and settings
Build a chart of accounts that supports New Zealand GST, annual accounts and management reporting without unnecessary detail. Map every source account to a Xero account and identify accounts to merge, archive or split. Configure tax rates, tracking categories, invoice settings, user access and lock dates. Avoid activating bank rules until the underlying coding has been tested.
Set the GST basis and filing frequency to match Inland Revenue. Confirm the first Xero GST period and how earlier filed returns will be treated. If payroll or external apps will integrate, test the account mappings before live transactions are posted.
Load and validate conversion balances
Xero’s conversion tools allow opening and historical balances to be entered or imported. Load receivables and payables at invoice level where those balances need to be managed in Xero. Confirm that the conversion balances create the correct balance sheet and retained earnings position and that the total debits equal total credits.
Validate bank balances, customer and supplier totals, GST, loans, fixed assets and shareholder accounts against the agreed source reports. Review the Historical Adjustment account and resolve differences. Imported history should be tested by month and by major account, not accepted merely because the overall balance agrees.
Run a controlled go-live and post-migration review
Connect bank feeds only after the conversion date and watch for overlapping statement lines. Enter or import the first live transactions and complete a sample bank reconciliation, sales invoice, bill, GST report and management report. Confirm user permissions and document the process for attachments, approvals and queries.
After the first month and first GST return, perform a formal review. Compare Xero reports with source-system closing reports and filed obligations. Record issues, correct mappings and update procedures. A successful migration is not simply an imported trial balance; it is a system that produces reliable bookkeeping and compliance information from the first live period.
Plan the first reporting cycle after migration
A migration is not complete when the opening balances import successfully. Schedule an early month-end review to confirm bank feeds, GST settings, invoice numbering, payroll links, document-capture tools and management reports are working as intended. Compare the first post-migration reports with the legacy system and investigate unexpected differences. Keep the old system accessible in read-only form for an agreed period so the preparer and New Zealand adviser can retrieve historical detail while the new Xero file becomes the primary accounting record.