 amount: €1,000.00 EUR Invoice currency selected: GBP (rate = 1.15) Display amount to customer: £1,150.00 (€1,000 × 1.15) Customer pays: £1,150.00 Conversion at payment: £1,150.00 / 1.15 = €1,000.00 EUR ✓ Invoice Details (Example 1): Base amount (USD): $1,000.00 Invoice currency: EUR Current exchange rate: EUR = 1.1 (1 EUR = 1.1 USD) Display amount to customer: €909.09 ($1,000 / 1.1) Customer Payment: Customer pays €909.09 on the payment form At payment time, system fetches current exchange rate (still 1.1) Payment is converted: €909.09 × 1.1 = $1,000.00 USD System checks: $1,000.00 >= $1,000.00 ✓ Payment covers invoice Payment is recorded as received Customer still pays €909.09 But this converts to €909.09 × 1.15 = $1,045.45 USD Payment exceeds invoice by $45.45