We're releasing an improvement to the Shopify admin that allows merchants to change their store's base currency after making their first sale.
Previously, to make a change to a store's currency after making sales, it was required to contact Shopify support to make this change on your behalf. Merchants can now make this change themselves from within the Shopify admin.
Note: for merchants using Shopify Payments, you can change the currency that your customers shop in through your Shopify Markets settings.
Read more about self-serve store currency changes in the Shopify Help Center.