Foreign Card Payments — Why Exchange Rate Calculations Differ

You completed a payment overseas.

The amount looked correct at checkout.

But when the charge appeared on your card statement,

the converted amount looked different.

Sometimes slightly higher.

Sometimes noticeably lower.

This happens because exchange rate calculations follow different processing stages.


Why Exchange Rates Differ in Card Payments

  • Authorization uses a preliminary network exchange rate
  • Final settlement applies the rate at posting time
  • Card networks update rates daily
  • Issuer banks may add conversion margins

Payment networks and issuing banks apply rates independently.


Authorization vs Settlement Conversion

  • Authorization shows an estimated converted amount
  • Settlement reflects the finalized exchange rate
  • Time gaps can change the rate applied
  • Weekend or holiday processing can shift timing

The posted charge reflects settlement — not authorization.


Additional Factors Affecting the Final Amount

  • Foreign transaction fees
  • Currency conversion fees
  • Dynamic currency conversion selections
  • Merchant settlement currency

When to Review or Dispute

  • If the conversion margin looks excessive
  • If duplicate foreign fees appear
  • If the merchant currency differs from checkout

Most exchange rate differences are normal processing results.