So, you're selling gift cards in multiple markets and several currencies - great!
What you might hear from some customers is that their gift card balance is actually worth a little more than they expected when they went to use it. This is expected, and is a result of how Shopify gift cards must always be stored in your store's default currency.
Example: US Dollar to Japanese Yen
One example of this happening is when currencies are far apart in terms of their exchange rate. One USD is equivalent to roughly JP¥ 149.41.
When the customer purchased a gift card in JP¥, they will be charged JP¥ 20,000.
In Givy, we store this balance as USD$133.86. Every hour, Shopify updates their currency exchange rates, and Givy adjusts the USD gift card balance so that the recipient always gets at least JP¥ 20,000. At the same time, Shopify's updates changes the exact value of US$ 133.86 to JP¥.
After several exchange rate updates, the current US$ balance may go up or down.
The gift card recipient will always see that their balance is the intended balance; in this case, JP¥ 20,000.
This also applies to any emails that are generated:
When the customer goes to use their gift card in the Japanese market, they will always get at least JP¥ 20,000. Sometimes, due to the conversion rates, this amount will be slightly larger than expected.
This does not have any negative impact on you, the merchant, since these differences are small fractions of a penny.