退款
退款始终采用客户用于支付订单的货币发放给客户。
当您发放退款时，以下规则将适用：
退款使用的付款方式与用于支付订单的方式相同。您无法将退款发放到其他的卡或银行账户。
退款采用客户用于支持订单的同一货币发放。如果客户采用欧元进行付款，他们则会收到以欧元为货币的退款。
如果需要对货币进行转换以用于退款，在转换时则会使用当前的货币汇率，而非下单时的货币汇率。转换付款金额时即会向您收取货币转换费，而不是在发放退款时才收取。当您发放退款时，不会退还货币兑换费和信用卡费。
如果您使用手动转换率，则会使用当前货币汇率计算退款。
货币风险
由于货币转化率存在波动，所以付款时的费率通常不同于退款时的费率。因此，您收到的订单的转换金额通常不等于您在退款中退还的转换金额。由于涉及货币转换，您可能会损失金钱或从中获利。
示例
您经营一家以美元或欧元出售的商店，并且款项货币是美元。一位首选货币为欧元的客户订购了一件 85 欧元的衬衫。付款时，1 欧元相当于 1.18 美元。客户支付衬衫费用后，欧元金额转换为 100 美元的支付金额。
| 产品 | 以客户的当地（出示）货币收到的金额 | 转换为您的款项货币的接收金额 |
|---|---|---|
| 衬衫 | 85 欧元 | 100 美元 |
几周后，客户决定退回衬衫。您将退还客户最初支付的 85 欧元。货币汇率波动，现在 1 欧元等于 1.29 美元。因此，您必须兑换 110 美元，比您最初从客户处收到的金额（100 美元）多 10 美元：
| 产品 | 采用客户使用的货币退还给他们的金额 | 从您的款项货币兑换的退款金额 |
|---|---|---|
| 衬衫 | 85 欧元 | 110 美元 |
在此示例中，由于货币汇率的波动，您损失了金钱。如果汇率朝相反的方向变化（例如 1 欧元相当于 1.05 美元），您则会从中获利。
Shopify商户官网原文详情：
Refunds
Refunds are always issued to a customer in the currency that they used to pay for the order.
When you issue refunds, the following rules apply:
Refunds use the same payment method that was used to pay for the order. You can't issue a refund to a different card or bank account.
Refunds are issued in the same currency that the customer used to pay for the order. If the customer paid in Euros, then they receive a refund in Euros.
If the currency needs to be converted for the refund, then the current currency rate, and not the currency rate at the time of the order, is used in the conversion. You're charged a currency conversion fee when the payment is converted, but not when a refund is issued. Currency conversion fees and credit card fees aren't returned to you when you issue a refund.
If you use a manual conversion rate, then refunds are calculated using the current currency rate.
Currency risk
Because currency conversion rates fluctuate, the rate at the time of the payment is often different from the rate at the time of the refund. As a result, the converted amount that you receive for the order usually doesn't equal the converted amount that you give back in the refund. You can gain or lose money with refunds because of currency conversions.
Example
You run a store that sells in USD and in EUR, and your payout currency is USD dollars. A customer whose preferred currency is Euros orders a €85 shirt. At the time of the payment, 1 Euro equals 1.18 US dollars. After the customer pays for the shirt, the EUR amount is converted to $100 USD for the payout.
Product Amount received in the customer's local (presentment) currency Amount received converted to your payout currency Shirt €85 EUR $100 USD A few weeks later, the customer decides to return the shirt. You refund your customer the amount that they originally paid, €85 EUR. The currency has fluctuated, and now 1 Euro equals $ 1.29 USD. As a result, you must convert $110 USD, which is $10 more than the amount ($100 USD) that you originally received from your customer:
Product Amount refunded to your customer in their currency Amount refunded that you had to exchange from your payout currency Shirt €85 EUR $110 USD In this example, you lost money because of the fluctuations in the currency rates. If the exchange rate moved in the opposite direction (for example, €1 EUR equalled $1.05 USD), then you would have gained money.
文章内容来源：Shopify商户官方网站
