# Foreign exchange mark-up

Whenever a customer makes a card transaction in a non-Euro currency, you must notify them of the difference between the VISA/Mastercard exchange rate and the European Central Bank (ECB) reference rate as a percentage markup for the transaction.

Solaris sends all of the required data points to inform your customers about the foreign exchange markup in the payload of the `CARD_AUTHORIZATION` webhook event. The `meta_info` object in the payload contains the following key properties:

* `fx_rate`: The current exchange rate.
* `fx_markup`: The difference in the exchange rate between VISA/Mastercard and the ECB.
* `issuer_fee`: The foreign exchange fee charged by the card issuer.
* `original_amount`: An object containing information about the original amount of the transaction, including the currency.


[View CARD_AUTHORIZATION webhook reference](/api-reference/onboarding/webhooks/webhook-events/paths/card_authorization/post)

**Notification example**

Use the following format to notify the customer of the FX markup rate:

> You spent 26 CHF (23,70 EUR) at {{name of merchant}} on your VISA card ending in 8765. The foreign exchange mark-up for this transaction is 0.3% over the European Central Bank rate.


[View the cards metadata object](/guides/cards/creation-and-servicing#appendix-vii-card-metadata-values)