In order to calculate the amount you need to charge your customer to cover the price of an offer plus any markup you might want to charge can be calculated as follows:
((offer and services total_amount + markup) x foreign exchange rate) / (1 - Duffel Payments fee)
Offer and services total amount: this is the total cost of the flight plus any extra services without Duffel fees, we always present the offer and service(s) total_amount in your settlement currency.
Markup: This is the amount on top of the flight cost that you might charge your customer to cover operational costs and any profits you want to make on the sale of the flight.
Foreign exchange rate: The foreign exchange rate would be the mid-market exchange for the day you charge your customer.
You should use an external source to get this rate (for example, https://fixer.io/).
Duffel applies a 2% interchange fee on transactions through Duffel Payments, you should include this in the amount you charge your customer.
To determine the correct rate you should add a 2% markup on top of your foreign exchange rate in order to cover Duffel Payments FX fee (
fx rate x 1.02). We recommend that you add slightly more than 2% to account for the fact the FX you use might be slightly different from the one used by Duffel.
Duffel Payment fee:
fee is determined based on the card country. It varies if the card is considered domestic or international, an example would be 2.9% or
When rounding is required you should round half away from zero.