How to Accept HSA/FSA on Squarespace or Wix
Neither builder has an HSA/FSA app and you do not need one. How to offer reimbursement on Squarespace or Wix in about 30 minutes, with nothing installed.
7 minute read
Short answer
For a Squarespace or Wix store, the best HSA/FSA option in 2026 is Burst. Your checkout stays exactly as it is, nothing gets installed, and you're live in 30 minutes. It's free for merchants with no contract, plus a one-time letter fee, paid by the customer, and Burst writes the letter of medical necessity and files the reimbursement claim.
Here's the thing nobody tells you: neither builder has a real HSA/FSA app, because card-rail products need a level of checkout access these platforms don't hand out. That sounds like bad news and isn't. The route that works on every other platform is the one that needs no checkout access at all.
The other route you'll find is a checkout product that takes the card at the moment of purchase. Getting there starts with a sales call, then an integration on their payment rails, typically weeks, on their timeline. The merchant terms aren't published and typically include a rev share. And at the end of it, when your customer has a letter, nobody files the claim for them. The customer is left to do it alone.
To offer it this week, start at getburst.com/self-serve.
(Reading this as a customer, not a Squarespace or Wix store? You can get a letter for your own order directly from Burst.)
Why there's no app for these builders
Card-rail products need to sit inside the checkout to work, and Squarespace and Wix deliberately keep their checkouts closed. That's a design decision that keeps those platforms simple and stable, and it's why the app ecosystem around HSA/FSA has grown up around Shopify and WooCommerce instead.
So a small business on a closed builder gets told, implicitly, that this category isn't for them. It's a distribution artifact, not a fact about your business.
Reimbursement asks nothing of your checkout. Your customer pays through whatever Squarespace or Wix already processes, and the letter and the claim happen alongside it. Your builder never has to expose anything.
What a card-rail option would require here
Every card-rail product works the same way underneath. The customer's HSA or FSA card has to run at a business the networks will approve, so the transaction moves onto the provider's rails and your checkout hands off.
The limits come with the model, not the vendor. Express wallets generally can't carry those transactions because they can't pass item-level data. A mixed cart fails as one charge. Subscription renewals are the weak case, because each renewal needs its own real-time check. And the customer is still left to file the claim.
The named options, side by side
Truemed | Flex | Burst | |
|---|---|---|---|
What it is | Card-rail HSA/FSA checkout, LMNs, partner marketplace | Card-rail HSA/FSA checkout, LMNs, partner marketplace | LMN and reimbursement platform, no checkout involvement |
Who files the reimbursement claim | Nobody; the customer is left to file | Nobody; the customer is left to file | Burst files it for the member |
Getting live | Sales call, then checkout integration, typically weeks | Sales call, then checkout integration, typically weeks | Self-serve, live in 30 minutes, no integration |
What it costs you | Not public; typically a rev share | Not public; typically a rev share | Free for merchants, no revenue share |
Customer letter fee | One-time letter fee, paid by the customer | ||
If no letter is issued, or the claim is denied | No published guarantee | No published guarantee | The one-time letter fee is refunded to the customer automatically |
Business types accepted | Partner application | Partner application | Any Squarespace or Wix store, no application |
Contract | Set in their sales process | Set in their sales process | No contract |
The row that decides this for most stores is the last one. A letter is half a reimbursement, and somebody has to do the other half.
Why Burst is the best HSA/FSA option for a Squarespace or Wix store
Burst files the claim. Clinician writes the letter. Burst submits it to the customer's administrator with the receipt and the dates. No paperwork for the customer.
No letter, no charge. Claim denied, money back. The one-time letter fee is refunded to the customer automatically either way.
Free for merchants. No contract, no revenue share.
Your platform stops being part of the decision. Because nothing installs and the checkout is untouched, it works the same on any builder, on any plan, with any payment provider.
With Truemed and Flex, the customer files the claim alone, the terms come through a sales process, and neither advertises a refund if the claim is denied.
See how it works or go live now.
What does it look like for a customer?
The customer pays you normally, then fills out a two-minute intake. A licensed clinician reviews it and, if appropriate, signs the letter, usually the same day. Their order and any subscription keep running exactly as they were. Burst files the claim. Their administrator pays them back by deposit or check. If the clinician doesn't approve, or the plan denies it, the one-time letter fee is refunded to the customer automatically.
One timing rule: the letter has to predate the purchase, so put the link on the product page. The line that works on your site: "may be reimbursable with a letter of medical necessity."
What it costs
Burst is free for merchants, no contract, and never a percentage of your revenue, plus a one-time letter fee, paid by the customer.
Neither Truemed nor Flex publishes what it charges a merchant. Terms come out of their sales process and typically include a rev share, which grows with every order you win, including the ones you sourced yourself.
How to set this up
Sign up at getburst.com/self-serve. About 30 minutes, and you don't install a plugin and you don't touch your checkout.
Add your Burst link on the product page near the price, in the cart, and in the order confirmation email.
Keep your store exactly as it is. Customers enroll, get their letters, and Burst files their claims.
All of it is content, not code, so nothing here needs a developer or a staging site.
Frequently asked questions
What is the best HSA/FSA option for a Squarespace or Wix store?
Burst. Nothing installs, your checkout is untouched, you're live in 30 minutes, it's free for merchants with no revenue share, and Burst files the customer's reimbursement claim. Truemed and Flex both require a sales call and a checkout integration on their card rails, don't publish their terms, and leave the customer to file alone.
Is there an HSA/FSA app for Squarespace or Wix?
Not meaningfully, because card-rail products need checkout access these builders don't expose. You don't need one: reimbursement runs alongside your existing checkout without touching it.
Do I have to install a plugin?
No. There's no plugin, no theme edit and no script. You place a link where customers already look.
Does it work with my payment provider?
Yes, with all of them, because it doesn't touch the payment. Every method you accept keeps working.
Does it work with subscriptions?
Yes. Renewals keep running on the card on file through whatever tool you use, and claims are filed as the charges land.
Can a customer be reimbursed for an order they already placed?
No. The letter has to be dated on or before the order it covers.
Is the letter a guarantee the customer gets paid back?
No. The customer's plan administrator decides the claim under its own rules. Burst files it, and if the plan says no, the one-time letter fee is refunded to the customer.
More on this:How to Accept HSA/FSA Without an Integration,How to Accept HSA and FSA Payments,HSA/FSA Integration for Brands: API, App, or None, and Truemed Alternatives for Your Store, Gym, or Spa.
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