Multi-currency accounting: what a system actually has to handle
Document currency, local-currency snapshots, dated rates, revaluation, and realised FX — the machinery behind “we invoice in dollars.”
Most products advertise multi-currency. Few make the ledger honest after the first foreign invoice. The gap is not a prettier currency picker — it is whether every posted document remembers what local currency meant on that day.
This guide is for finance leads who already feel the pain: banks in one currency, customers in another, and a board pack that somehow never ties. If you are still single-currency, you can stop here — you do not need this complexity yet.
Document currency is not the same as view currency
The invoice the customer receives is in a document currency (USD, EUR, …). The books of record are in a local currency (LCY). A useful system stores both: the face amount and an authoritative LCY amount captured with the rate that applied when the document posted.
“View in USD” on a report is a presentation choice. It must not rewrite historical journals. If your only FX feature is converting the P&L at today’s rate, you have a spreadsheet with a login screen.
Dated rates beat a single year-end card
Exchange rates move. Statutory and management views that convert each posting at the rate as of the posting date will not match a naive sum of foreign balances at the closing rate. That is not a bug in arithmetic — it is two different questions.
Importing history (for example from Dynamics NAV) without the dated rate log guarantees you will fight the same P&L vs balance-sheet gap every close. Keep the rates; do not “simplify” them away.
Revaluation vs settlement
Open foreign AR/AP need period-end revaluation so unrealised FX hits the P&L while the invoice is still unpaid. When cash lands at a different rate, the difference versus the carried LCY balance is realised FX.
Teams that park everything in one “FX difference” account without labelling unrealised vs realised spend the next audit explaining noise. Separate the events even if both post to FX accounts.
What to demand in a demo
Ask the vendor to post a foreign invoice, show the LCY snapshot, change the rate, revalue the open item, then settle and show realised FX. If any step is “we export to Excel,” you are buying a report, not a ledger.
Omnizone’s finance and receivables modules are built around that path. If your company will stay one currency for years, stay on simpler books — multi-currency discipline is cost you should only pay when the business needs it.
Related modules
Related guides
- Moving off accounting software: what breaks and when
- Migrating from Dynamics NAV without losing your history
Related glossary
FAQ
Can we keep operational invoices in USD and only revalue at year end?
You can, but material open balances will misstate monthly P&L. Most mid-market teams revalue at each period close, then realise FX on settlement.
Does Omnizone store rate × amount as floats?
No. Amounts are integer minor units (cents) with a scaled rate snapshot — the same discipline as the live posting engine.