You can definitely add a discount to your recurring order when you set it up at the checkout! Simply enter your code into the gift cards/promos box at the checkout to apply the code to your ongoing order.
If you have already set up your recurring order and wish to swap your code, you can do so either by updating your payment information and adding a new code at the checkout before your next order processes, or by cancelling your recurring order in your account and starting fresh.
Updating your payment information can be done on your Recurring Order Page by looking for this button at the top of the page:
Top tip: Specific recurring order discount codes, the ones that typically begin with YF-RO, are the best codes to apply on your recurring order because they don't expire as quickly! Not to mention, they usually give you the biggest discount. If you choose to use a regular discount code on your order, they will expire in line with our terms and conditions.