Swap to subscription: turn a one-time purchase into a subscription

What it does

Swap to subscription is a post-purchase offer. Right after checkout, the customer sees an offer to change the product they just bought into a subscription of the same product.

If the customer accepts:

The subscription starts and the customer pays for the first delivery.
Kaching Upsell refunds the one-time product they bought.
The order now has only the subscription line.

The customer does not pay twice. They get the subscription price (plus your first-delivery discount, if you set one) instead of the one-time price.

💡 Good for: consumables and repeat products (coffee, supplements, skincare, pet food) where a subscriber is worth more than one order.

Before you start

You need:

Products with subscription plans (selling plans). Any subscription app works, for example Kaching Subscriptions. Only active products count. Draft and archived products are left out.
Access to your locations. When you set up the first Swap to subscription offer, Shopify asks you to allow Kaching Upsell to read your locations. The app needs this to refund and cancel the swapped product. If you do not allow it, you cannot create the offer.
The post-purchase page. This offer works only on the post-purchase page (after payment, before the thank-you page). It does not work on the checkout or thank-you page.

Set up the offer

1. Create the offer

In Kaching Upsell, go to the home page and click Create upsell offer.
Select Swap to subscription.
Click Set up offer.
If Shopify asks for access to your locations, click to allow it.

The editor opens with the following defaults:

10% off the first delivery
Refund taxes: on
Refund shipping: off
Offer texts in your store's language

2. Triggers - which products can be swapped

Under When a product is bought once which of them to upsell to a subscription?, select one:

All products with plans - every active product that has a subscription plan.
Specific products - only the products you pick. The product picker shows only products with subscription plans.

3. Offer - What to offer

This step lists the products from your trigger. For each product you see the first-delivery price, the price after that, and the plan. Example: "€26.99 first delivery · then €29.99 · Delivery every month".

For each product you can:

Choose the plans the customer can pick. Expand the product card and select or clear plans. At least one plan must stay selected.
Preselect a plan. Click Preselect next to a plan. The customer sees this plan as a first.
Replace the image. Click the image icon.

Offer replacement if target product quantity is greater than 1. Off by default. Then the offer shows only when the customer bought 1 unit of the product. If you turn it on, the offer will appear for 2 or more units. All units are refunded and the subscription is for 1 unit.

4. Offer - Pricing

Discount - an extra discount on the first delivery, on top of the plan's own discount.

Percentage (for example 10% off) or a fixed amount (for example €5 off).
Clear the checkbox for no extra discount. The customer then pays the plan price.
Later deliveries are at the regular plan price.

Use custom discount title - change the discount name the customer sees.

Refund for the bought product - what the customer gets back for the one-time product:

Refund taxes - on by default.
Refund shipping - off by default. The app refunds shipping only when nothing else in the order ships.

The first delivery of the subscription always ships free.

5. Style and texts

The default texts:

Title: "Switch to a subscription and save"
Text: "We'll refund the item you just bought and start your subscription instead. Your first delivery ships free. Skip or cancel anytime."
Button: "Subscribe & get {{refund}} back"
Decline: "No thanks, keep my one-time purchase"

The {{refund}} variable shows the amount the customer gets back for the bought product. Make sure your texts match your settings. For example, if you turn off "Refund taxes" or your subscription app does not allow skips, change the text.

To see the offer with a real product, use Preview an order with above the preview.

When the offer shows

The offer shows only when all of these are true:

The order has a product from your trigger, bought as a one-time purchase.
That product (and the variant the customer bought) has a subscription plan that you allow in the offer.
The quantity is 1, or "Offer replacement if target product quantity is greater than 1" is On.
The order does not already have a subscription product - Shopify allows only one subscription in an order.

When more than one product qualifies

The customer sees one swap offer for one product. One order can have only one swap, because Shopify allows only one subscription in an order.

The app picks the product like this:

It takes every product in the order that qualifies (see the list above).
It sorts them by line total, highest first. The line total is the amount the customer paid for that line, so a line of 2 units can come before a more expensive single unit (only when "Offer replacement if target product quantity is greater than 1" is on).
It offers the first product it can offer. If the variant the customer bought has no plan you allow, the app goes to the next product.

If the same product is in the order twice (for example two variants), the app uses the line with the higher total.

👉 Example: the order has Coffee beans (€30) and a Coffee filter (€8), both with subscription plans. The customer sees the offer to swap the Coffee beans. The Coffee filter stays a one-time purchase.

You cannot set the order yourself. To prevent a product from being swapped, select Specific products in the trigger and do not pick that product.

If there are more offers after the swap (for example in a funnel), they can offer products only as one-time purchases. Products sold only on subscription are not shown.

What happens after the customer accepts

The customer pays for the first subscription delivery.
Usually within a few seconds, the app refunds the one-time product. Unfulfilled units are cancelled, so they do not ship. The post-purchase page waits up to 20 seconds for the refund, so the thank-you page shows only the subscription.
The refund amount follows your refund settings (product price, plus taxes and shipping if turned on).

Special cases:

The subscription payment does not go through: the app does not refund the one-time product. The customer keeps their original order.
The order is cancelled: no refund is made by the app.
The product already shipped: the app refunds it without restocking and adds the tag Kaching Replaced Line Shipped to the order.
The refund fails: the app tries again for about 30 minutes. If it still fails, it adds the tag Kaching Replace Refund Failed to the order. Refund the one-time product manually in Shopify, because the customer has paid for both orders.

💡 Tip: create a saved order view in Shopify for the tag Kaching Replace Refund Failed and check it.

Analytics

Revenue of a swap = the first subscription payment minus the refund of the one-time product. This is often negative at first.
Each renewal of the swapped subscription is then added to the offer's revenue (renewals in the 12 months after the swap). Over time the offer shows the real value of the new subscriber.
Renewals add to revenue only. They do not change the order count or the conversion rate.

FAQ

Can I use it on the checkout or thank-you page?

No. It works only on the post-purchase page.

Do I need Kaching Subscriptions?

No. Plans from any subscription app work. Kaching Subscriptions is one option.

Does the customer get charged twice?

For a short time, yes: they paid for the one-time product and the first delivery. The app refunds the one-time product right after the subscription payment. If the refund fails, the order gets the tag Kaching Replace Refund Failed and you must refund it manually.

Is the subscription for the same quantity?

No. The subscription is always for 1 unit.

Can I A/B test it?

Yes, like other post-purchase offers.