Accept HSA/FSA Payments for Your Business

Make HSA/FSA payments your next revenue driver

Increase AOV by 50% and checkout conversion by 30% with the only HSA/FSA payments infrastructure built for top health and wellness brands.

Flex is trusted by thousands of leading brands across the health and wellness industry

Transform checkout. Drive more revenue.

See what leading brands achieve by accepting HSA/FSA payments with Flex.

CONVERSION LIFT

+30%
More shoppers complete checkout with HSA/FSA

HIGHER AOV

+50%
Customers spend more using health benefit funds

FEWER RETURNS

-10%
Fewer returns when buyers use pre-tax dollars

REPEAT BUYERS

92%
Of customers said they'll return because of HSA/FSA

Your all-in-one HSA/FSA payments infrastructure

Everything you need to accept HSA and FSA payments and support complex enterprise operations at scale.

HSA/FSA Payment

Not enough HSA/FSA funds? Split your payment.

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CVV

Pay with HSA/FSA

Seamless HSA/FSA Payments

Accept HSA/FSA payments in-app or on your website. Flex handles the complexity and compliance for your business.

Let's see if you qualify for a Letter of Medical Necessity! What's your DOB?

03/09/1990

What conditions are you seeking treatment for? Select all that apply.

Your Answer

Simplified HSA/FSA Eligibility

Manage HSA/FSA eligibility before and after purchase, with physician-reviewed Letters of Medical Necessity when required.

Subscriptions

Unlock recurring HSA/FSA revenue with subscription payments.

Split Payments

Let customers split HSA/FSA payments with another method.

Off-Session Payments

Save payment methods for seamless future charges.

Reimbursements

Enable customers to easily submit HSA/FSA reimbursements.

Advanced Analytics

Track HSA/FSA performance to understand customer behavior and drive more revenue.

Streamlined Reporting & Exports

Generate HSA/FSA reports to track performance, reconcile transactions, and drive decisions.

Equinox at our core has always had a focus on preventive health and longevity. This is why we're excited about our partnership with Flex, which supports healthcare-aligned services without compromising the member experience.

Parinda Muley
Strategy & Commercial Leader

Flexible integration for modern e-commerce

Integrate Flex into your existing stack, support complex operations, and unlock new revenue with HSA/FSA payments.

curl --request POST \
  --url https://api.withflex.com/v1/checkout/sessions \
  --header 'Authorization: Bearer ' \
  --header 'Content-Type: application/json' \
  --data '{ \
  "checkout_session": {\
    "allow_promotion_codes": true,\
    "line_items": [\
      {\
        "price": ",\

API-first and fully customizable

Flex integrates seamlessly with your tech stack, from custom checkouts to Shopify. Our HSA/FSA payments infrastructure adapts to how you sell.

Built for enterprise scale

Handle high SKU counts, large transaction volumes, and evolving business models with infrastructure designed for enterprise brands.

Fast, reliable implementation

Get up and running quickly with clear docs and a proven integration process.

Hands-on support

Support for your team and your customers, from integration to ongoing operations.

A new revenue channel

Flex connects you to high-intent HSA/FSA customers to drive new revenue.

Integrate with any checkout or payment system

Flex works with your existing checkout and payment systems, so you can start accepting HSA/FSA with ease.

See why leading brands choose Flex

See how health and wellness brands are unlocking new revenue with HSA/FSA through Flex.

“Flex empowers our customers to invest in fitness using their HSA/FSA funds.”

Michael Maas
Chief Sales Officer

“Our partnership with Flex helps make holistic wellness more accessible to everyone.”

Natasha Trindall
General Manager

“We chose Flex because it offers the most comprehensive solution for enabling HSA/FSA payments.”

Lisa Thorson
Director Regulatory Affairs

“Flex improved our conversion rate and added trust at checkout.”

Raechelle Hoki
VP of Marketing

“Since the launch of this collaboration, we've seen a notable increase in HSA/FSA transactions, driving both customer satisfaction and revenue growth.”

Forrest Smith
CEO and Co-founder

“Flex helps make cutting-edge fitness more affordable and accessible.”

Ulrich Dempfle
Co-founder

Flex HSA/FSA payments frequently asked questions

Find answers about accepting HSA and FSA payments, and how Flex helps grow your business.

How does HSA and FSA payment processing work?

Is the process to accept HSA & FSA card payments the same as other payment methods?

Is my business eligible to accept HSA & FSA payments?

Do Flex HSA/FSA payments adhere to the IRS guidelines?

Do I need a different tool to provide Letters of Medical Necessity to my customers at checkout?

What if my customer wants to split their purchase between their HSA/FSA card and a credit or debit card?

Can Flex HSA/FSA payments handle subscriptions and memberships?

Does the Flex HSA/FSA checkout integration work with coupons and promotions?

Does Flex integrate with any ecommerce website?

Does Flex offer an API for integrating HSA/FSA payments into my checkout?

How do I get started accepting HSA/FSA payments?

Start accepting HSA/FSA payments to drive more revenue

Get Started