This playbook connects an AfterSell upsell offer, a Shopify Flow, and a Stay workflow so the upgrade happens the moment a customer accepts the offer.
Before you begin, make sure you have:
AfterSell installed and connected to your Shopify checkout
Shopify Flow enabled on your store
Admin access to create a product in Shopify
Access to build workflows in your Stay merchant portal
How this works
Three systems work together for this upgrade path:
AfterSell presents the quarterly upgrade offer post-purchase and adds a trigger product to the order if accepted.
Shopify Flow tags the order when that trigger product is present.
Stay watches for the tag and updates the customer's subscription — changing both quantity and billing interval.
📌 Note: This path is specific to AfterSell's post-purchase upsell.
1. Configure the Upsell Offer in AfterSell
Set up the trigger and offer so AfterSell knows when to present the quarterly upgrade.
Set the trigger
In your AfterSell offer configuration:
Under Product/Collection, select the product that should trigger the upsell offer.
Set Product Quantity to match the quantity of the trigger product (e.g., 1).
Under Variant on Subscription, select the same trigger product so the upsell only fires when that product is part of a subscription order.
Create the upsell offer product
In Shopify, create a new product to represent the upgrade — name it something identifiable, such as "Upgrade to Quarterly on Next Order."
Use this product as the upsell offer in AfterSell.
📌 Note: This product is a placeholder, not something the customer keeps. When a customer accepts the upsell, it's added to their order as a signal — Shopify Flow and Stay use its presence to trigger the actual subscription changes in the next two steps.
💡 Tip: Give this product a name your team will immediately recognize in order tags and reports later, since it's the anchor for the rest of this workflow.
2. Tag the Order with Shopify Flow
Create a Shopify Flow that tags the order whenever a customer accepts the upgrade offer.
In Shopify Flow, create a new workflow.
Set the trigger to AfterSell Post-Purchase Offer Accepted.
Add a condition confirming the product ID includes the ID of your "Upgrade to Quarterly on Next Order" product.
Add an action to add the order tag
90_day_upsell.
📌 Note: This tag is what Stay looks for in the next step to identify which orders need the subscription update.
3. Build the Upgrade Workflow in Stay
Create a Stay workflow that watches for the tag and applies the actual subscription changes.
To set this up:
In the Stay AI Merchant Portal, click Subscription Setup and then click Workflows.
Set the Trigger to A Subscription Order Is Updated.
Set the Condition to Order tag equals
90_day_upsell.Add the following Actions:
Change Quantity — select the variant ID of the product that triggered the upsell, then update the quantity (e.g., from 1 to 3).
Change Billing Interval — update the billing interval to match the new supply (e.g., from every 30 days to every 90 days).
Save the workflow.
⚠️ Warning: Quantity and billing interval must both be updated together. If only one changes, the customer's cadence and order size will fall out of sync — for example, billing every 90 days but still shipping a 30-day quantity.
✅ Best Practice: Match your quantity change to the actual supply duration of the upgraded product. If your "3-pack" product is a 90-day supply, the quantity and billing interval should both reflect that ratio.
For example
A customer subscribed to a monthly single-pack accepts an AfterSell post-purchase offer to upgrade their next order to a quarterly 3-pack. AfterSell adds the "Upgrade to Quarterly on Next Order" product to the order.
Shopify Flow detects it and tags the order 90_day_upsell. Stay's workflow picks up the tag, updates the subscription quantity from 1 to 3, and changes the billing interval from every 30 days to every 90 days, all without the customer or your team touching the subscription manually.