February 2026
Multi-Category LMN Support
Flex can now support multi-category Letters of Medical Necessity during checkout. If your brand sells different types of products, such as skincare and supplements, customers can select multiple health conditions within a single session. When approved, multiple LMNs are provided to the customer within the same checkout flow, reducing friction and improving completion rates for mixed carts.
Improved LMN Chat Performance
We’ve optimized the performance of the Letter of Medical Necessity (LMN) chat interface to reduce latency and improve responsiveness. Customers now move through the consultation more smoothly, creating a better experience that helps improve completion rates and overall conversion. LMNs provided through Flex continue to be clinically reviewed. This update will be rolled out to merchants over the next few weeks.
Setup Mode
Create checkout sessions in setup mode, allowing customers to save their HSA or FSA card without being charged immediately. This supports workflows like off-session billing, where the card can be charged later for one time payments or recurring purchases. The checkout experience will adapt to show a simplified card-saving flow.
Enhanced Dispute Management
We’ve built full dispute handling into the Flex API. This includes visibility into dispute status, management capabilities, and the ability to submit responses directly through Flex. Merchants are able to manage disputes end-to-end without relying on external systems.
Checkout Session Actions
Manage checkout sessions directly from the Dashboard with a new actions dropdown. For sessions using manual capture, you can capture authorized payments, cancel uncaptured holds, or reauthorize expired payment intents, all without needing to contact support or use the API.Quick Create Price
Added the ‘Create Price’ action to the quick create menu making it faster and easier to create a price from any page.Improved Payment Decline Messages
Checkout now surfaces the more specific error message from the card issuer when an HSA/FSA payment is declined.Refund Page Improvements
Added a max refund button and small UX improvements to the refund flow.HSA/FSA Card Detection
We’ve enhanced how Flex identifies HSA/FSA cards using BIN lookup data. This update improves underlying payment classification and supports future functionality.Card Funding
The funding field is now exposed on the Card API response.January 2026
Checkout Session Expired Webhook Event
You can now subscribe to the checkout.session.expired webhook event to get notified when a checkout session ends without a completed purchase. This lets you know when a customer drops off, enabling follow-up workflows like abandoned cart recovery or broader checkout performance analysis.
Custom Fees for Shopify & WooCommerce
Merchants using Shopify or WooCommerce can now include custom fees in Flex checkout sessions. These may include recycling fees, service charges, or other surcharges. Fees appear clearly in the checkout summary using the custom name provided.To use this feature, add an array of fees to the checkout_session object when creating a session.
Custom Checkout Text Now Supports Linking
Custom checkout text now supports hyperlinks. Links open in a new tab to prevent customers from leaving the checkout flow. This is useful for linking to terms of service, return policies, HSA/FSA eligibility guides, or support pages, helping reduce customer confusion by providing easy access to important information during checkout.
Improved Create Price Modal
The create price modal on the Payment Links page has been redesigned for better speed and usability. It now includes cleaner styling, a dedicated currency input, and more reliable form handling, making it easier to add prices when setting up new payment links.Consultation Fee Handling
Improved how Flex handles consultation fees for customers who do not qualify for a Letter of Medical Necessity.Receipts for Subscription Trials
Improved receipts to more accurately display one-time charges alongside free-trial subscription items when purchased together.Shipping Display Name
Shipping options now support a custom display_name field in webhooks and API responses for clearer identification.Split Payment Helper Text
Updated checkout messaging to better explain split payment options and reimbursement steps when HSA/FSA funds are insufficient.Off-Session LMN Redirect Support
Off-session charges that require a Letter of Medical Necessity now return a next_action redirect instead of an error.Dashboard Pagination Improvements
Improved pagination behavior across dashboard pages.December 2025
Redesigned Flex Marketplace
We’ve launched a fully redesigned Marketplace to improve how consumers discover HSA/FSA-eligible brands. With better navigation, enhanced search, and dedicated category pages, it’s now easier for shoppers to find what they need. The new structure also lays the foundation for product-level discovery, coming soon. These updates are designed to improve visibility, drive higher intent traffic, and help merchants grow their revenue. Shop Now.
Custom Fees at Checkout
Merchants can now apply custom fees directly to a checkout session, including recycling fees, service fees, or other surcharges. These fees are automatically distributed proportionally across eligible and ineligible items, ensuring accurate HSA/FSA handling in mixed carts.To use this feature, add an array of fees to the checkout_session object when creating a session.
Custom Checkout Text
Merchants can now add custom text to select areas of the Flex checkout experience, giving you more control to inform your customers during checkout. This can be done via the API by including the custom_text property when creating a checkout session.
Subscription Payment Method Updates
Merchants can now generate a shareable URL that allows customers to update their payment method on an active subscription. This improves flexibility, reduces churn from expired or invalid cards, and enables more robust subscription management through both the Flex Dashboard and API.Example API request:
Redesigned Notification Emails
Flex notification emails have been migrated to Postmark’s template system to improve formatting, ensure consistent branding, and increase reliability across customer communications. This update applies to key touchpoints, including Letters of Medical Necessity, purchase receipts, and reimbursement notifications.November 2025
Redesigned Dashboard Overview
We rolled out a redesigned Dashboard Overview that makes your HSA/FSA channel easier to measure and optimize. The new experience brings together expanded metrics (like AOV, customer conversion, and returning customer rate), clearer performance insights, and a modern interface that highlights what’s driving growth. Read more.
New RevenueCat Integration
Our new partnership with RevenueCat now enables compliant HSA/FSA payments directly inside your iOS, Android, and web apps. With just two setup steps, developers can unlock a new pre-tax revenue stream for eligible digital health subscriptions. Read more.
Shopline Integration
Flex is now integrated with SHOPLINE, making it easy for merchants to accept HSA/FSA payments directly at checkout. Setup takes only a few clicks, helping SHOPLINE’s 600,000+ merchants tap into consumers using their pre-tax health dollars. Read more.September 2025
Analytics
The new Analytics tab in the dashboard gives you clear visibility into your HSA/FSA channel—so you can quickly see what’s working, spot drop-offs, and identify which customers and products drive the most value. Track key metrics like AOV, sales, conversion rate, and more. This is our first iteration of Analytics, and we’ll be expanding it with deeper insights in future releases.
Payouts API
Access the same reconciliation details you see in payments exports — now directly via API for automated workflows.
Order Summary
We’ve updated how order summaries appear at checkout, giving customers a clearer view of their purchase and boosting confidence before payment.
Dashboard ARN and Client Reference ID Visibility
You can now view both Acquirer Reference Numbers (ARNs) and Client Reference IDs directly in the dashboard. This makes it easier to track transactions end-to-end, resolve disputes quickly, and align with your internal systems.
Checkout Session Filters & Reimbursements
New statuses and filters make it easier to review past checkout sessions, including those that are reimbursements.August 2025
Flex Secures $15M in Series A
We’re excited to announce Flex’s $15M Series A funding round led by First Round and Core VC, and Cameron Ventures with continued support from Rethink Impact, YC, and Liquid2.Since launching, we’ve been on a mission to modernize HSA/FSA payments. In that time, we’ve helped retailers like you unlock new revenue streams by making it simple for customers to spend their pre-tax health dollars directly at checkout.This funding allows us to expand our reach across the enterprise space, helping even more health and wellness brands grow—and making healthcare spending easier and more accessible for millions of Americans.Thank you for being part of our journey. We couldn’t do this without your partnership and trust.
Expanded API Capabilities
We added two new fields payment_intents and amount_received fields to checkout sessions. This enables you to see each checkout session’s associated payments, whether they were made via partial purchase or split cart, all in one API call.
Line-Item Tax Support
We now support tax at the line item level, enabling tax handling across different product categories.
Improved WooCommerce Plugin Stability
We resolved conflicts with other WordPress plugins, ensuring seamless compatibility with Flex.July 2025
Shopify Subscription Support
We now support Shopify subscriptions with HSA/FSA reimbursement. After a customer checks out, they’ll be prompted to complete a Letter of Medical Necessity post-purchase. If approved, they’ll receive the documents needed to submit a reimbursement to their provider. Dashboard tracking is coming soon to help you measure reimbursement success.
Checkout Customizations
You can now customize the Flex checkout to better match your brand. Add your logo, adjust the colors, and create a more consistent customer experience from start to finish.
Improvements to Partial Purchase
Your customers can now choose how much of their order to place on their HSA/FSA card. This improved flow helps maximize pre-tax benefit usage and reduces failed payments, leading to better conversion and a smoother checkout experience.June 2025
Reports Page & Exports
You can now export key reports directly from the Flex dashboard — no custom requests or workarounds needed. Customize your date range before exporting to save time and avoid post-processing. This is just the beginning — more reports and analytics are on the way.
RevenueCat integration
Introducing the new Flex RevenueCat Integration. Connecting your subscription-based app to HSA/FSA payments used to require custom development and manual workarounds. Now, setup just takes a few clicks with no heavy lifting required. With the Flex and Revenue Cat integration it’s easy to offer compliant, tax-free payment options for eligible subscriptions, without disrupting your current flow. Reach out to your account manager to test the integration.
Dashboard Onboarding
Getting started with Flex is now faster and easier. New merchants can access onboarding directly in the dashboard — from connecting payouts to inviting team members, everything you need to launch is now in one place. Don’t worry — if you still need help, Benny will be there to assist you.
Updated Documentation
The Flex docs just got a major upgrade. We’ve added an AI assistant to help answer questions in real time, improved search to help you find the right article faster, introduced an interactive API reference so you can test endpoints directly from the page, and added a changelog so you can track what’s new as we continue to ship.May 2025
WooCommerce
Introducing the new Flex WooCommerce Integration. Access to the $150B in tax-free HSA/FSA funds on WooCommerce used to mean complex development, unclear documentation, and no support. Flex simplifies everything with a clean, minimal-dev integration that handles payments, compliance, and support so you don’t have to. Reach out to Flex to get started with WooCommerce.
Off-Session API
Flex now supports off-session payments — the ability to charge a customer when they’re not actively present in the checkout flow. This will enable Flex to create more automated, seamless payment experiences for merchants, while maintaining full compliance and reliability behind the scenes. With off-session payments, you can let shoppers skip re-entering payment info for a faster checkout experience.
Dashboard Navigation
Flex dashboard updates are here — and it’s just the beginning. We’ve refreshed the look, revamped navigation, and added a collapsible sidebar so you have more room to work and quicker access to the pages you use most. Stay tuned for more updates focused on making your workflows faster, smoother, and smarter.
Shopify Marketing App
We’re launching a new Flex Shopify Marketing app to help you drive awareness, educate customers, and increase conversion — all with just a few clicks. The app makes it easy to add assets like product badges and modals directly to your Shopify store. It’s currently in review, and your account manager will follow up as soon as it’s approved.April 2025
Partial Purchase
We’ve launched Partial Purchase, a powerful new feature designed to improve conversion for merchants with higher-priced products or higher average order values.If an HSA/FSA card is declined due to insufficient funds, Flex will now charge the available balance on the HSA/FSA card and prompt the user to enter a credit or debit card to complete the purchase.
Order + Subscription Page
The dashboard Order and Subscription pages have a new look. We’ve combined key data — including line items, customer info, payment details, and developer data — to give you a more holistic view of each checkout session.
Filter By Email
You can now filter by customer email on both the Order and Subscription Summary pages, making it easier to quickly locate the relevant record. A full suite of filters is in the works and coming soon.