Multi-currency migrations, done properly

The four rules

1. The home currency decision is permanent. In QuickBooks Online (and most cloud systems) the base currency cannot be changed after the company is created. It is the first thing we confirm in writing, because the only fix for getting it wrong is starting again.

2. Historical transactions must keep their original exchange rates. A EUR invoice from 2024 was booked at that day's rate. Re-importing it at today's rate changes your debtor balances, your P&L and your tax history all at once — and it looks fine until someone reconciles. Our imports carry the original rate on every foreign-currency transaction.

3. Unrealised gains are policy, not arithmetic. Period-end revaluations of open foreign balances differ by system and by your accountant's practice. We migrate the revaluation history you have, flag where the old and new systems compute differently, and hand your accountant a note of exactly what changed — rather than pretending the systems agree. For a worked revaluation example and a pre-cutover checklist, see our QuickBooks multi-currency cleanup guide.

4. Reconciliation is per currency, or it is not reconciliation. A trial balance that ties in your home currency can still hide a EUR debtor error offset by a GBP creditor error. We reconcile each currency's subledger separately — bank by bank, debtor by debtor — before cutover.

What we need to see before quoting

The currency list actually in use · which bank accounts are foreign-denominated · whether open invoices/bills exist in foreign currencies (and roughly how many) · and your period-end revaluation habit, if any. That is enough for a fixed quote — usually within one business day, by email.