Guides

Mixed carts: subscription and one-time items

Understand why a cart with subscription and one-time items shows two shipping lines or two fulfillments, and what you can change

When a customer buys a subscription and a one-time item in the same checkout, Shopify can split shipping in two. The order can show two shipping lines, two charges (one of them $0), or two fulfillments. This is Shopify checkout behavior. Awtomic has no special logic for mixed carts. This article explains what you see, what you can change, and what the subscription is charged on later renewals.

Symptoms

  • "The order has two shipping lines."
  • "I'm printing two labels for one order."
  • "The order has two fulfillments, one for the subscription and one for the one-time item."
  • "The first order shows two shipping charges, and one of them is $0."
  • "One-time items are charged shipping while the subscription ships free."
  • "How do I make the whole cart free when it has a subscription in it?"
  • "Shipping is added twice when the cart has a subscription and a one-time item."

Quick checks

  1. Is the plan's Enable subscription shipping setting on? In Awtomic, go to Subscription plans and open the plan. The checkbox is under Shipping, at the bottom of the Discount card in the Pricing section (on prepaid plans, at the bottom of Payment options in Prepaid terms, or in the Pricing section on multi-order prepaid plans). If it is on, subscription items use the Awtomic Subscription Shipping profile, and one-time items use their own profile.
  2. Do your subscription rates differ from your normal rates? If they are the same, you may not need a subscription shipping profile.
  3. Is a delivery customization or shipping app active? In Shopify admin, go to Settings → Shipping and delivery and look for Delivery customizations (Shopify's guide: add a delivery customization). If any are active, turn them off and retest before you treat this as Shopify behavior.
  4. Is your free shipping offer an automatic discount? In Shopify admin, go to Discounts and check its type. If yes, it doesn't apply to subscription items. See Free shipping on the subscription does not cover one-time items.
  5. Is one of the two shipping charges $0? If yes, that is a normal split, not a double charge. Add the two lines to get what the customer paid.

Causes and fixes

Shopify creates separate delivery groups

Why it happens: When subscription items and one-time items use different shipping profiles, Shopify puts them in separate delivery groups. A delivery group is Shopify's name for a set of items in one order that ship together. Each group gets its own shipping line, and can become its own fulfillment. Several subscriptions in the same cart can share one shipping line when their billing and delivery policies match.

How to confirm: Open the order in Shopify admin. Look at the shipping lines and the fulfillments. One group holds the subscription items, the other holds the one-time items.

How to fix:

  • If your subscription rates are the same as your normal rates, you do not need a subscription shipping profile. Turn off Enable subscription shipping on the plan so both item types use the same profile. See Set up subscription-specific shipping rates.
  • To ship everything in one box, open the order in Shopify admin before you fulfill it. In the Unfulfilled section, click … and choose Merge fulfillment. You can only merge fulfillments from the same location. Shopify explains this under fulfilling orders.

What to expect: A $0 line next to a paid line is one charge, not two.

The subscription rate is added to the one-time rate

Why it happens: Shopify's help says that when a subscription app's shipping profile applies to a mixed cart, the app's rate is added to the one-time items' rate. On a cart with only subscription items, only the subscription rate applies. See how Shopify combines rates from different shipping profiles and troubleshoot third-party app shipping profiles.

How to fix: Set your subscription rates with this in mind. For example, a $0 subscription rate means the customer pays only the one-time items' shipping.

Free shipping on the subscription does not cover one-time items

Why it happens: A $0 subscription rate covers the subscription delivery group only. One-time items keep the rate from their own profile. Shopify automatic discounts do not apply to subscription items, so an automatic free-shipping discount does not help either.

How to fix: Choose one:

  • Accept that one-time items pay their normal shipping rate.
  • Use theme or cart logic that applies a free-shipping discount code when the cart contains a subscription item.
🚧

Important

A code applied by cart logic can be reused.
A customer can add a subscription, get the code, then remove the subscription.
Limit the code to orders that include a subscription, or accept that risk.

See Free shipping for subscriptions.

A delivery customization or shipping app changes mixed-cart rates

Why it happens: Delivery customizations and shipping apps can hide, rename or re-price rates. Some fail only on mixed carts.

How to fix: Turn them off one at a time and retest checkout. See Shipping apps and delivery customizations.

What the subscription is charged on renewals

Renewals charge only the subscription items. One-time items are not part of the subscription, so their shipping is not charged again.

🚧

Important

The rate on the subscription can be lower than the shipping on the first order.
Shopify stores the cheapest rate for the subscription items, and the first order's shipping can also cover your one-time items.
Every renewal charges the stored price.
Check the subscription's Shipping row in Awtomic to see what the next renewal will charge.

To change the stored rate, see Edit the shipping rate in a subscription. For how the stored rate works, see How a subscription's shipping rate is set and when it changes.

What Shopify controls

  • Separate delivery groups and shipping lines for subscription and one-time items.
  • Adding the subscription rate to the one-time rate on mixed carts.
  • Automatic discounts not applying to subscription items.
  • One delivery method for the whole order. A customer cannot pick up one part and ship the other.

Awtomic does not split, merge or re-price mixed carts at checkout.

If you use an AI agent

  • Ask it to compare the order's shipping lines in Shopify admin with the subscription's shipping row in Awtomic.
  • Ask it to list active delivery customizations and shipping apps before it concludes this is Shopify behavior.
  • For developers: with Shopify Admin API access, it can read order.shippingLines to list each shipping line and its price.
  • Full guide: Debug subscription shipping with your AI agent.

Still stuck? Send support this

  • Your shop domain (yourstore.myshopify.com).
  • The order number and the subscription ID.
  • A screenshot of the order's shipping lines and fulfillments.
  • Screenshots of the plan's Enable subscription shipping setting and the profile's zones and locations.
  • Any free-shipping discount you use, and whether it is automatic or a code.
  • Any delivery customizations or shipping apps that are active.
  • What you already checked from this article.

Related

Updated 5 days ago

Did this page help you?