A currency movement is not a customer payment

The local-currency debtor total falls
Imagine your business has an invoice denominated in a foreign currency. The local-currency value in the management report falls between reviews, but the customer has not made a payment.
Do not classify the entire reduction as successful collection. The reported amount may have moved because of currency translation or another adjustment rather than a receipt that increased the bank balance.
Keep the original currency amount visible
Record the invoice currency and outstanding amount in that currency alongside the local reporting value. Confirm the report's exchange-rate date and method with the accountant.
Avoid comparing a foreign-currency invoice figure directly with a local-currency bank balance. The units need to be clear before the team can understand what changed.
Reconcile actual transactions first
Identify payments, agreed credits and other supported transactions during the period. Keep those separate from changes arising solely from the reporting conversion.
Use the relevant bank and accounting records rather than estimating a receipt from the difference between two reports. A lower translated balance is not evidence that the customer has paid any particular amount.
Ask the accountant to explain the residual
Have the accountant identify the appropriate treatment of exchange differences and any remaining reconciliation item. This article is about management clarity, not a prescription for accounting entries or tax treatment.
business.gov.au's record-keeping guidance includes invoices, payments and banking information. Those linked records help distinguish a genuine transaction from a movement in how the same balance is presented.
Source: business.gov.au: Record keeping
Keep forecast conversion assumptions explicit
Where future cash is expected in another currency, state the basis used to estimate the local amount and label uncertainty. Use professional advice where the exposure is material or contractual currency terms are unclear.
Do not treat a favourable recent exchange movement as guaranteed or assume the invoiced amount will translate at today's rate when eventually received. Avoid making an unexamined currency assumption part of a payment promise to someone else.
Explain the next debtor movement in two parts
At the next review, show actual collections separately from translation and other adjustments for material foreign-currency accounts. Retain the reconciliation and unresolved questions.
The business can then assess collection progress using receipts rather than appearances. A clear explanation protects the cash forecast from treating a reporting movement as money that has become available to spend.