How to upgrade customers to a subscription after checkout
UpsellPlus can sell subscriptions on the post-purchase page in two ways. For one-time buyers, it offers the subscription version of what they just bought, adds it to the order and refunds the original item. For existing subscribers (on Recharge, Appstle, Seal Subscriptions or Stay AI), it upgrades their subscription to a bigger or better plan, without charging them again.
- One-time → subscription: post-purchase offer with a subscription product + Product Replacement behavior
- Existing subscription upgrade: connect your subscription app under Integrations, then use the same type of offer
- Requires: products with subscription selling plans, and permission for UpsellPlus to manage orders
Why it works this way
Shopify doesn't allow removing an item from an order that's already placed, or adding a subscription to an order that already has one. UpsellPlus works around both:
- One-time buyers: the subscription item is added to the order, and the original item is refunded afterwards.
- Existing subscribers: the offer is accepted on the order at $0, and UpsellPlus then updates the shopper's subscription in your subscription app.
Upgrade one-time buyers to a subscription
- Go to Offers → Create Post-Purchase Offer (or add a step to an existing funnel).
- On the Offers tab, choose the product and click Add as a subscription, then Choose a selling plan (or several plans, so the shopper can pick a frequency).
- On the Behavior tab, under How should this offer work?, choose Product Replacement.
- Turn on Refund the item being replaced. Once the order is paid, UpsellPlus refunds the original item at the price the shopper paid.
- Approve the order permission if Shopify asks for it.
- Save and activate the funnel.
Good to know:
- Only items bought as a one-time purchase can be upgraded this way. The offer is skipped if the order already contains a subscription.
- The shopper is charged for the subscription and refunded for the original separately, so both appear on their statement. Refunds take a few minutes to issue and several days to reach their bank.
Upgrade existing subscribers (Recharge, Appstle, Seal, Stay AI)
1. Connect your subscription app
Go to Integrations in the UpsellPlus menu and connect your app:
App | How to connect |
|---|---|
Recharge | In Recharge, go to Tools & apps → API tokens and create a token with read access to Orders, Plans and Store, and read and write access to Subscriptions. Paste it in UpsellPlus. |
Appstle Subscriptions | Click Connect Appstle, then in Appstle go to More → Integrations → Partner Integrations and approve UpsellPlus. |
Seal Subscriptions | In Seal, go to Settings → General Settings → API and copy the API token and API secret. Paste both in UpsellPlus. |
Stay AI | In Stay AI, go to Settings → API Keys and create a key with Read Subscriptions, Update Subscriptions and Read Orders permissions. Paste it in UpsellPlus. |
2. Create the upgrade offer
Create a post-purchase offer with the subscription product and plan you want to upgrade shoppers to, and choose Product Replacement as the behavior (same steps as above). To show it only to subscribers, add the Subscription in Cart targeting rule.
When a subscriber accepts, UpsellPlus updates the subscription that was created by this order. They aren't charged again on this order; the new plan applies from their next billing.
FAQ
Will the shopper be charged twice?
One-time buyers are charged for the subscription and refunded for the original item. Existing subscribers aren't charged again on this order; their subscription is updated instead.
Which subscription apps are supported for upgrading existing subscriptions?
Recharge, Appstle Subscriptions, Seal Subscriptions and Stay AI.
Can shoppers choose their delivery frequency?
Yes. Attach several selling plans to the product and the shopper picks one from a dropdown in the offer.
What if my subscription app rejects the connection later?
The Integrations page shows a warning. Reconnect (paste a new token, or approve again in Appstle) to resume upgrades.
Related articles
- How to build a post-purchase upsell funnel
- How to upgrade to subscriptions dynamically (Dynamic Subscription)
- How to upsell to a subscription in checkout and cart
- Why can't I accept the subscription after installing UpsellPlus?
Updated on: 14/10/2026
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