We have recently identified an issue in Shopify itself that has led to international customers receiving higher discounts than they are eligible to from our app.

The cause is that Shopify is actually using a different rate to convert prices to local currencies, than is provided by the Shopify Geolocation app.

For example, one of our customers has a product available for $54 USD, and 2 shipping discounts: $10 off shipping for orders over $150 USD, and $20 off shipping for orders over $250 USD.

The currency conversion rate the Geolocation app provides from USD to CAD when I tested was 1.3788166. This is also the currency conversion rate provided to Regios Discounts.

However, in the cart and checkout, the price of the $54 USD is converted to $81 CAD by Shopify. This implies a ratio of 1.5, which is a major difference from the rate we are given.

As you can imagine, this is a significant difference in ratio, and leads to incorrect calculations. Our app only receives the CAD prices and 1.3788166 rate from Shopify when trying to calculate discounts - there's no way for us to get the prices in USD without calculating it ourselves.

To convert prices back to USD, so that we can test against your minimum/maximum purchase requirements/etc., our app's code divides the subtotal of $363 CAD shown in the attached screenshot by the 1.3788166 rate. This leads to the subtotal being calculated as $263.27 USD, which is why the "$20 off shipping for orders over $250 USD" is applying, when in reality, the cart subtotal was $242 USD. Instead, the $10 off discount should have applied.

We're reaching out to Shopify to get to the bottom of what exactly is going on here, but it may take time to receive a response from them.