> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aftersell.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Adding an item to an existing subscription

**Add another subscribable item to subscription** is a Subscription Upgrade type that adds a brand-new product to a customer's existing subscription, instead of changing the frequency or swapping the product they already subscribe to. The item joins their subscription and recurs on the same cadence from then on.

Use it when you want to grow the value of a subscription rather than change it. For example, a customer subscribed to monthly coffee beans accepts an offer to add a bag of filters to that same monthly delivery.

New to Subscription Upgrades? Start with the [Overview](/aftersell/subscription-upgrades). For the full wizard walkthrough, see [Setup & configuration](/aftersell/subscription-upgrades-setup).

## How it differs from the other upgrade types

The other three upgrade types modify what the customer already subscribes to. Add-item leaves the existing subscription intact and adds to it.

| Upgrade type                                      | What happens to the existing subscription                                                |
| ------------------------------------------------- | ---------------------------------------------------------------------------------------- |
| Change delivery or billing frequency              | Same product, new cadence.                                                               |
| Replace with a different product                  | The subscribed product is swapped for another.                                           |
| Both – change frequency and replace product       | Both of the above.                                                                       |
| **Add another subscribable item to subscription** | **Nothing is changed or removed. A new item is added alongside what they already have.** |

## What the customer experiences

1. **Buys a subscription.** The customer completes checkout on a product with a subscription selling plan.
2. **Sees the offer.** On the post-purchase page they see the item you configured, at the price you set.
3. **Accepts.** The displayed price is charged on that Shopify order, with no re-entry of payment or shipping details.
4. **The item joins their subscription.** In Recharge, Skio, or Loop, the item is added to their subscription and bills with it on every following cycle.

The cadence is always inherited from the customer's existing subscription. You do not set a frequency for the added item, and you cannot set one — the whole point of add-item is that the new product ships and bills together with what the customer already receives.

## Setting it up

Add-item is configured in **Step 3: Subscription upgrade** of the Subscription Upgrade wizard.

1. In your Aftersell dashboard, go to **Post-purchase funnels**.
2. Click **Add Funnel** and select the **Subscription Upgrade** template.
3. Complete Step 1 (connect your provider) and Step 2 (pick the trigger product) as normal.
4. In Step 3, set **Subscription upgrade type** to **Add another subscribable item to subscription**.
5. Under **Item to add to the subscription**, click **Choose item to add** and pick the product (and variant, if it has variants).
6. Complete Step 4 (offer product) and click **Create offer**.

<Note>
  The item you pick here must have an **active selling plan**. Only products with active selling plans appear in the picker, because the added line has to be a recurring line in your subscription platform. This is a different field from the Step 4 offer product, which is the visual placeholder the customer sees in the offer card.
</Note>

Aftersell validates the configuration against your provider when you save, using the same checks that run when a funnel is activated. If your provider cannot run the offer as configured, the wizard tells you before you save rather than letting it fail after a customer has been charged.

<Warning>
  If you switch your connected provider to one that does not support add-item, a saved add-item offer resets to **Change delivery or billing frequency** and the added item is cleared. Re-check the offer's configuration after changing providers.
</Warning>

## Provider behaviour

All three supported providers can add an item to a subscription, but they realize it differently, and the difference is visible to the customer. The wizard shows the relevant description for your connected provider when you select the add-item type.

### Skio and Loop

The item is added as a **recurring line on the existing subscription**. No second subscription is created, and no other line on the subscription is modified.

* The displayed price is charged on the current Shopify order.
* The item is then added to the subscription and billed with it **from the next order onward**.

### Recharge

Recharge has no add-a-line API. Aftersell instead creates a **second subscription** for the added item that inherits the cadence of the customer's existing subscription, anchored to that subscription's **existing next charge date** — so the two bill together rather than the new one charging straight away.

* The item is added and charged now, so it ships in the next delivery.
* It then recurs on the same cadence as the original subscription.

<Note>
  On Recharge, the customer will see **two subscriptions** in their Recharge portal: their original one, and one for the added item on a matching cadence. They are billed on the same cadence but are separate subscription records, so the customer can manage or cancel the added item independently.
</Note>

### At a glance

|                                      | Skio                                        | Loop                                    | Recharge                                                                             |
| ------------------------------------ | ------------------------------------------- | --------------------------------------- | ------------------------------------------------------------------------------------ |
| How the item is added                | Recurring line on the existing subscription | Recurring line on the existing contract | Second subscription inheriting the cadence                                           |
| Subscriptions in the customer portal | One                                         | One                                     | Two                                                                                  |
| First recurring charge               | Next order                                  | Next order                              | Next order — the sibling is anchored to the existing subscription's next charge date |
| Prepaid subscriptions                | Not supported                               | Not supported                           | Supported                                                                            |

## Limitations

* **No discounts.** Add-item offers do not support a first-order or recurring discount. Selecting the add-item type hides the recurring-discount section in Step 3; the **First-order discount** field in Step 4 still appears, but whatever you type there is saved as `0`. Set the price you want on the Step 4 offer product instead.
* **Prepaid subscriptions are not supported on Skio or Loop, but only Skio is checked when you save.** Skio rejects adding a recurring line to a prepaid subscription, so Aftersell validates the trigger product's selling plans at save time: it blocks the offer when every plan on the variant is prepaid, and warns when only some are. Loop gets no equivalent check — a Loop add-item offer on a prepaid trigger saves cleanly and then fails when a prepaid subscriber accepts it, so verify the trigger yourself on Loop.
* **The added item must have an active selling plan.** On Loop in particular, the variant must have a selling plan or the provider rejects the add.
* **Failed add-item calls are retried.** Add-item is part of the automatic retry workflow like the other upgrade types. Re-issuing it can't stack quantity, because each provider's execute step carries a dedupe guard that recognises an item already added. A failure with a cause that a replay can't fix — rather than a transient one — is routed to manual reconciliation instead of being retried forever.
* **Adding an item the customer already subscribes to behaves differently by provider.** On Skio and Loop, the existing line's quantity is incremented. On Recharge there is no add-line API, so the item becomes its own sibling subscription — leaving the customer subscribed to it twice, on two separate subscriptions. Choose an item your trigger-product subscribers are unlikely to already have, especially on Recharge.
* **One subscription change per post-purchase flow.** As with the other upgrade types, only the first accepted subscription offer in a funnel goes through.

## Related

* [Setup & configuration](/aftersell/subscription-upgrades-setup)
* [Limitations & important notes](/aftersell/subscription-upgrades-limitations)
* [Fulfillment & 3PL mapping](/aftersell/subscription-upgrades-fulfillment)
* [Troubleshooting](/aftersell/subscription-upgrades-troubleshooting)