Shopify Subscriptions

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Overview

• Customers complete subscription purchases via ShopPay (or any Shopify-supported payment method).
• After checkout, they receive a reimbursement link that generates their HSA/FSA documentation.
• Merchants are billed per reimbursement letter generated.

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Customer Journey

1. Customer completes subscription checkout in Shopify.
2. On the Thank You page (or in the order confirmation email), they see a link to “Get HSA/FSA Documentation.”
3. Clicking the link opens a Flex-hosted form (payment link without payment).
4. Customer submits required info and receives a Letter of Medical Necessity (LMN).
5. Customer submits the itemized receipt and LMN to their HSA/FSA administrator to reimburse each invoice.
6. These documents are valid for 1 year.

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Integration Steps

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Option 1 — Add to Thank You Page

1. In Shopify Admin, go to: Settings → Checkout → Customize.
2. Select the Thank You page template.
3. Add a new block (e.g., Custom HTML) with your reimbursement link and call-to-action text.

   ⚠️ You need Shopify Plus for this feature.

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Option 2 — Add to Order Confirmation Email

1. In Shopify Admin, go to: Settings → Notifications → Customer Notifications.
2. Select Order confirmation and click Edit code.
3. Insert your reimbursement link and call-to-action into the email template.

💡 Tip: You can pass the Shopify order ID as client_reference_id and customer email as a URL parameter to pre-fill the Flex form for a smoother customer experience.

https://checkout.withflex.com/test/pay/l/fplink_01k18vwxbeknstaq51q0eq24j4?client_reference_id={{ order.id | url_encode }}&email={{ customer.email | url_encode }}&first_name={{ customer.first_name | url_encode }}&last_name={{ customer.last_name | url_encode }}

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Limitations

• Shopify subscriptions cannot use HSA/FSA cards directly.
• Customers must complete a separate reimbursement step after each invoice.
• LMNs may only be used to reimburse invoices dated the same day or up to one year in the future.
  After that, customers should request a new LMN.

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Example Email & LMN

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FAQs