Pay a supplier in their currency, book the difference honestly
An importer's bill arrives in US dollars and is paid weeks later at a different rate; the difference is a real gain or loss and belongs in the books. SeroBooks stores the face value in the supplier's currency and the rate on the day, converts to your home currency for the ledger, and posts the realised gain or loss when the payment settles. A per-supplier exposure view and a period-end revaluation report show what is still open — the report reports; it does not post.
What you get
Realised versus unrealised
A realised gain or loss is a fact: the bill was booked at one rate and paid at another, and the difference is income or expense in the period of payment. An unrealised one is an estimate: what the open bills would be worth at today's rate. SeroBooks posts the first automatically and reports the second, because whether and when to book a revaluation is an accounting policy your accountant sets, not something software should decide at midnight.
Frequently asked questions
Where do exchange rates come from?
You enter the rate on the bill and on the payment. Amazon advertising spend in a foreign currency is converted at the Bank of Canada daily rate automatically, but bills are yours to rate.
Can I invoice a customer in US dollars?
Not today. That is one of the few things on this site's honesty ledger that is still open.