Start with the evidence
Capture the amount and currency exactly as shown on the source document. Keep any converted working figure in a separate labelled field rather than overwriting the original.
Work through the example
An EUR100 receipt is shown as USD110 using a fictional USD1.10 per EUR rate. Both amounts matter: one is the source amount and the other is the result of a stated calculation.
Make the next step clear
Retain the rate context and ask the reviewer which conversion method applies to the actual record. Do not present the example rate as a current quote or an approved business policy.
Keep the source context
All exchange rates in these worked examples are fictional arithmetic inputs, not current market rates. A business must use the source, date and method appropriate to its own review and approved accounting process. Keep original currency amounts available throughout.