Decide two things first
The cut-over date, when the old system stops and the new one starts, and how much history you bring. Opening balances alone are quick, but you lose the detail behind them. Full history takes longer and lets you run every old report in the new system. For audit-heavy businesses we recommend full history.
The order that works
- Clean the masters: close duplicate customers, suppliers and items before you export anything
- Map the chart of accounts, old code to new account, and agree it with the finance team
- Import masters first: accounts, customers, suppliers, items, then tax codes
- Import transactions month by month: invoices, bills, receipts, payments and journals
- After each month, compare the trial balance with the old system before moving on
What to reconcile
- Trial balance, account by account, for every period
- Customer and supplier balances, invoice by invoice
- Bank balances against statements
- Stock quantities and values, if you carry inventory
- VAT reports, if you are registered
Before you switch off the old system
- Run both systems side by side for one closing month
- Train the team on the new month-end routine
- Keep a read-only copy of the old data for audits
- Write down every mapping decision, so the auditor can follow it
We have moved full accounting history from server-based systems into Odoo, QuickBooks Online, Zoho Books and others, checking the trial balance period by period. If you are planning a move, we are happy to look at your data first and tell you honestly how long it will take.