Why is my HSA/FSA card being declined?

Last updated: February 18, 2026

If your HSA/FSA card is being declined during checkout, there are several common reasons and solutions to try:

Make sure you're using the correct payment method

The most common issue is not selecting the proper payment option at checkout. You must select "Pay with Flex | HSA/FSA" as your payment method, not the regular credit card option. If you use the standard checkout flow, your HSA/FSA card will likely be declined automatically.

Bank restrictions and fraud protection

Your bank may be blocking the transaction for security reasons. Common scenarios include:

  • Fraud protection: Your bank flagged the transaction as potential fraud

  • "Do Not Honor" decline: Your bank is blocking the transaction and requires you to contact them directly

  • Card activation: Your HSA/FSA card may need to be activated

Contact your HSA/FSA card issuer to verify there are no restrictions on your account and that your card is properly activated.

Fidelity HSA/FSA cards

If you're using a Fidelity HSA/FSA card, they sometimes direct customers to use a personal card at checkout for certain product categories instead of allowing the transaction to go through directly. This is a known issue we're working to resolve with Fidelity.

Alternative solution: Pay with personal card

If your HSA/FSA card continues to be declined, you can still complete your purchase by:

  1. Selecting "Pay with Flex" at checkout

  2. Using a personal credit or debit card instead of your HSA/FSA card

  3. Completing the medical consultation if required

We'll automatically provide all the necessary documentation (itemized receipts or Letter of Medical Necessity) for you to submit a manual reimbursement claim to your HSA/FSA administrator.

Still having issues?

If you've tried the above steps and are still experiencing problems, please contact us at support@withflex.com with:

  • The website where you're trying to make the purchase

  • The email address you're using at checkout

  • Any error messages you're seeing

We're here to help ensure you can use your HSA/FSA funds for eligible purchases.