Troubleshooting HSA/FSA Card Declines

Last updated: October 27, 2025

If your HSA/FSA card is being declined when trying to make a purchase through Flex, there are several common causes and solutions to try.

Make Sure You're Using Flex Checkout

The most common issue is not selecting "Flex | Pay with HSA/FSA" as your payment method at checkout. HSA/FSA cards will not work through regular credit card checkout flows due to merchant category codes.

Important: When you use regular checkout instead of Flex checkout, your HSA/FSA card may be declined because the transaction appears as an "electronic sale" rather than a "medical sale" to your HSA/FSA provider. Flex uses proper medical merchant category codes only when you complete the Flex checkout flow.

To use Flex checkout:

  1. Add eligible items to your cart

  2. Proceed to checkout

  3. Look for and select "Pay with Flex" or "Flex | Pay with HSA/FSA" as your payment method

  4. Complete the eligibility questionnaire

  5. Enter your HSA/FSA card information

If Flex Option Isn't Visible

If you don't see the Flex payment option:

  • Log out of Shop Pay: Click "Checkout as Guest" at the bottom of the checkout page if you're automatically signed into Shop Pay

  • Complete all checkout steps: Some sites require you to fill out shipping information before payment options appear

  • Check the correct product page: Make sure you're purchasing from the HSA/FSA eligible product listing

Common Decline Reasons

"Do Not Honor" or "Transaction Not Allowed"

These are generic decline codes from your card issuer. Contact your HSA/FSA card provider or the bank that issued your card to:

  • Verify there are no restrictions on your account

  • Ask them to lift any transaction blocks

  • Confirm the merchant category is approved

  • Confirm that medical merchant category codes were used (this only happens when using Flex checkout)

Fidelity HSA/FSA Cards

Fidelity has updated their policy and may not allow direct HSA card purchases for certain product categories. If you have a Fidelity card and it's being declined, you can:

  • Use a personal card to complete the purchase through Flex checkout

  • Submit the documentation we provide for manual reimbursement through your Fidelity portal

Card Velocity Exceeded

If you've made multiple purchase attempts in a short time, your card issuer may flag this as suspicious activity. Contact your card provider to clear this restriction.

Alternative Solution: Manual Reimbursement

If your HSA/FSA card continues to be declined, you can:

  1. Complete your purchase using a personal credit or debit card through the Flex checkout flow

  2. Receive the Letter of Medical Necessity and itemized receipt from Flex

  3. Submit these documents to your HSA/FSA administrator for reimbursement

Note: You must still use the Flex checkout flow (not regular checkout) to receive the proper documentation for reimbursement.

Still Need Help?

If you continue to experience issues after trying these solutions, contact Flex support at support@withflex.com with:

  • The email address you used for checkout

  • Screenshots of any error messages

  • The specific website where you're trying to make a purchase