Subscriptions are controlled in two places: the Purchase type setting, and the optional Has subscription condition.
Purchase type
In the Purchase type card, Applies to has three options:
One-time purchases (the default)
Subscription purchases
Both one-time & subscription
If you include subscriptions, choose how many payments get the discount under Recurring payments for subscriptions:
Limit discount to the first payment
Limit discount to multiple recurring payments (2 or more)
Discount applies to all recurring payments
If your store doesn't sell subscriptions, this setting is locked to One-time purchases.
Has subscription condition
Use this condition to control eligibility based on what's in the cart:
Contains subscription: at least one subscription item.
Does not contain subscription: no subscription items at all.
Subscription only: every item is a subscription.
Mixed (subscription + one-time): at least one of each.
Examples
Free shipping on subscriptions only. Set Purchase type to Subscription purchases, and choose how many renewals get it.
One-time orders only, no subscriptions in the cart at all. Set Purchase type to One-time purchases, and add Has subscription → Does not contain subscription. This also excludes mixed carts.
Good to know
"First payment" means the first order of each subscription, not the customer's first order ever. A customer who starts a second subscription gets the discount on that one's first payment too.
Renewal shipping is often set by your subscription app. Some apps (for example Loop) recalculate shipping on renewals using their own settings. If renewals are charged shipping when they shouldn't be, check your subscription app's shipping settings too.
An item counts as a subscription only if it's sold on a recurring selling plan. Pre-orders and try-before-you-buy plans count as one-time items.
Works with subscription apps that use Shopify's selling plans.
Subscription items count toward Cart total and Cart subtotal like any other item.