Issue with Discount Amount in Shopify API Response

[JohnWick1]

I’m applying a fixed amount discount of $420.89 for draft order create API, but the response from the API shows different amounts in the amount Set object.

#### **API Request:**  
I applied the following discount:  
```json
"appliedDiscount": {
  "title": "RR Exchange Discount",
  "value": 420.89,
  "valueType": "FIXED_AMOUNT",
  "description": "RR Exchange Discount",
  "amountSet": {
    "presentmentMoney": {
      "amount": "330.44",
      "currencyCode": "GBP"
    },
    "shopMoney": {
      "amount": "427.2",
      "currencyCode": "USD"
    }
  }
}
```

#### **Issue:**  
- I expected the discount to be **$420.89**, but the API response shows:  
  - **USD (shopMoney):** `$427.2` (higher than applied)  
  - **GBP (presentmentMoney):** `$330.44`  

Questions:
- Why is the shop Money amount ($427.2) different from the applied discount ($420.89)?
- How does Shopify handle currency conversions for discounts?
- Is there a way to ensure the exact discount value is applied without fluctuations?

Any insights from the community would be greatly appreciated!

[JoshGood]

Hi there,

I'm not used to using this particular API, but I do know that Shopify automatically converts the discount amount to the shop’s base currency (USD in your case). This conversion uses the exchange rate at the time of the API call, which may introduce slight variations. The amount you set ($420.89) likely went through an internal conversion process, resulting in $427.2. Exchange rates update multiple times per second during trading hours in the Forex market, and the market operates 24 hours a day, five days a week (Sunday evening to Friday evening, U.S. time), meaning exchange rates fluctuate continuously during that time. This is most likely why the amount changes from what you initially expected.

Currently, Shopify doesn’t provide a way to enforce a fixed discount value across multiple currencies due to real-time exchange rate conversions. However, you can try the following:

• Use percentage discounts instead (valueType: "PERCENTAGE"). This ensures the applied discount scales correctly, regardless of currency fluctuations.
• Manually pre-convert the discount based on the latest exchange rate before passing it to the API (though Shopify might still adjust it slightly).
• Confirm the exchange rate used by checking amountSet values and adjusting accordingly in your logic.

[JohnWick1]

Thanks for your response!

Is there any way to retrieve the exchange rate via Shopify’s API? I’d like to fetch the exact conversion rate Shopify is using to understand the discrepancy in the discount amount. Does Shopify provide an endpoint for this, or is there a recommended approach to get real-time exchange rates within the platform?

[JoshGood]

No problem!

Unfortunately, my knowledge of Shopify APIs is still pretty new and limited, so I am not sure if there is a way to retrieve the current rate without an external API outside of Shopify. However, I would assume external APIs may also not update as frequently (or accurately) as Shopify.