WooCommerce Buy Now, Pay Later: What Affirm, Klarna and Afterpay Cost

On this page 7 sections

1. What WooCommerce Buy Now, Pay Later Costs per Order
2. Affirm, Klarna and Afterpay Fit Different Carts
3. Gateway Toggle or Provider Plugin
4. The Break-Even Test: How Many BNPL Orders Must Be New
5. Set Eligibility Rules and Messaging Before Launch
6. Test Refunds on a Live Order First
7. Start With Your Margin and Your Promo Date

Key takeaways

• Through Stripe or WooPayments in the U.S., Affirm and Afterpay cost 6% + 30¢ and Klarna costs 5.99% + 30¢. A card costs 2.9% + 30¢. On a $300 order, BNPL costs about $9.30 more.
• To check whether BNPL pays for itself, divide the fee gap by your gross margin minus your card fee rate. The answer is the share of BNPL orders that must be sales you would otherwise lose.
• Stripe may switch on Klarna or Affirm at a temporary 2.9% + 30¢ rate. Standard pricing starts automatically later, so write down the date it ends.
• Klarna Pay in 4 isn't supported in New Mexico or Hawaii, and Afterpay through Stripe stops at $4,000. Set payment rules so shoppers don't see an option that will fail.

You can add WooCommerce buy now, pay later options in two ways: switch on Affirm, Klarna and Cash App Afterpay inside WooPayments or the Stripe plugin, or install a provider's own plugin under a direct contract. Either way, the provider pays you the full order amount up front and collects the installments from the shopper. You pay for that with a fee about double a card sale: Stripe's published U.S. price is 6% + 30¢ for Affirm and Afterpay and 5.99% + 30¢ for Klarna, against 2.9% + 30¢ for a standard online card payment.

That gap is worth paying only if enough BNPL orders are sales you would otherwise have lost, and you can work out that threshold before you turn anything on.

What WooCommerce Buy Now, Pay Later Costs per Order

The rates below come from Stripe's local payment methods pricing page and are charged per successful payment. WooPayments, which is built on Stripe, lists the same BNPL rates and the same 2.9% + $0.30 domestic card rate for U.S. merchants, according to eSEOspace's review of WooPayments fees. Confirm them on the fee page in your own account.

Stripe adds 1.5% for international transactions on Afterpay and Klarna, plus 1% when currency conversion is required. The page doesn't say which accounts get the enhanced Affirm rate, so check which one your account shows.

Direct contracts are less transparent. Klarna's pricing annex for U.S. and Canadian merchants, dated September 2023, lists a 5.99% variable fee and a $0.30 fixed fee for Klarna Payments with U.S. customers. It also reserves the right to add a cross-border fee for sales outside the U.S. and Canada. Stripe's own guide to Afterpay puts Afterpay's merchant fees at 3% to 6% per transaction, with lower rates negotiable above a certain monthly volume. Whoever you sign with, get the policy on fees for refunded orders in writing along with the rate.

Check Whether You're on an Introductory Rate

Stripe's pricing page says some businesses qualify for temporarily reduced rates on Klarna and Affirm, which Stripe turns on after notifying you. Those methods run at 2.9% + 30¢ for at least one month, then standard pricing applies unless you disable them. If BNPL buttons appeared on your checkout without you adding them, this is the likely reason. Note when the promotion ends. On that day your fee on a $300 BNPL order goes from $9.00 to $18.27 for Klarna and $18.30 or more for Affirm, and nothing on your checkout will remind you.

Affirm, Klarna and Afterpay Fit Different Carts

All three offer an interest-free Pay in 4 plan. They split apart on larger orders.

Afterpay's limits are the clearest in print. Stripe's Afterpay documentation gives these U.S. ranges: Pay in 4 for carts from $1 to $2,000, interest-bearing 6- or 12-month loans for carts from $400 to $4,000, and no Afterpay option above $4,000. A store selling $40 to $150 apparel fits easily. A store selling $5,000 sofas never sees the button.

Affirm reaches further. Stripe describes it as Pay in 4 every two weeks or monthly installments of up to 36 months, depending on location. Terms that long suit furniture, fitness equipment and electronics.

Klarna covers the middle, with Pay in 4, pay in 30 days and monthly financing shown in Stripe's Klarna materials. Stripe's Klarna docs list three restrictions that matter to U.S. stores. Pay in 4 isn't supported in New Mexico or Hawaii. Klarna financing isn't supported in Iowa, West Virginia or Massachusetts. And Klarna doesn't support B2B payments, so leave it off a WooCommerce wholesale portal.

Each provider also approves each shopper for a spending amount at checkout, so a cart inside your store's range can still be declined, and you won't see why.

Gateway Toggle or Provider Plugin

WooPayments lets you turn on Affirm, Afterpay and Klarna from one settings screen without opening separate merchant accounts, per DevDiggers' 2026 roundup of WooCommerce BNPL plugins. Stripe's own plugin draws on the same Stripe-hosted methods. The tradeoff is control.

For a first launch, the toggle is the sensible default: one contract, one payout, one place to refund. A direct contract earns its extra bookkeeping when you want promotional 0% financing on big tickets or have the volume to negotiate. If you're still picking the base gateway, our WooPayments vs. Stripe comparison for WooCommerce covers that decision. The store owner's checklist for choosing a WooCommerce payment gateway lists what to compare.

BNPL is an add-on to card processing, not a replacement. Your core WooCommerce payment processing setup still sets the cost of every card order, and that's where what you actually pay per WooCommerce sale gets decided.

The Break-Even Test: How Many BNPL Orders Must Be New

A common shortcut divides the extra BNPL fees by your margin to get the "extra sales needed." It ignores the BNPL fee on the new sales themselves and treats every BNPL order the same. There are two kinds. An order from a shopper who would have paid by card anyway costs you only the fee gap. An order you would otherwise have lost earns your full margin minus the full BNPL fee. The real question is what share of BNPL orders has to be the second kind.

Worked example (illustrative numbers). Assumptions: a $300 average order, a 40% gross margin, and Afterpay or standard Affirm through WooPayments or Stripe at 6% + 30¢. Shoppers who would have bought anyway would have paid by card at 2.9% + 30¢. The store takes 100 BNPL orders a month, and basket size doesn't change.

Each order that would have happened anyway costs an extra $9.30 ($18.30 minus $9.00). If all 100 fall in that group, BNPL costs you $930 a month and earns nothing. Each truly new order brings in $120 of margin minus the $18.30 BNPL fee, or $101.70. Break-even is where new orders times $101.70 equals the other orders times $9.30. Solving that gives 8.4 orders. So if roughly 9 of every 100 BNPL buyers would not have bought without it, BNPL pays for itself, and every new order past that is profit.

The shortcut for your own store: divide the fee gap by your gross margin minus your card fee rate. Here that's 3.1 ÷ (40 − 2.9), or about 8.4%. The fixed 30¢ is the same on both sides, so it barely moves the answer.

The table corrects a popular assumption. Ticket size alone doesn't make BNPL pay off; margin and fee tier do. The $1,200 furniture store on standard Affirm needs about the same share of new buyers as the $300 store, and the enhanced rate lifts its bar from about 10% to 16%. The thin-margin accessories store needs almost one BNPL buyer in five to be a sale it would otherwise have lost.

You can't see who would have bought anyway, so use proxies. Compare checkout conversion and average order value over equal periods before and after launch, with no other promotions running. Our checkout conversion rate benchmarks help you read the result. Count the BNPL buyers who are returning customers that used to pay by card, because those orders are the likeliest to be pure fee gap.

Set Eligibility Rules and Messaging Before Launch

Not every product belongs behind a BNPL button. Gift cards and store credit are the obvious exclusions. Subscription products are another, unless your provider explicitly supports recurring billing. Stripe's Klarna docs name the U.S., Germany and Sweden as the only countries where Klarna's Pay Later option supports subscription payments. Hide the option on carts outside the provider's range, such as Afterpay above $4,000, and on any product the provider restricts in its acceptable-use policy. WooCommerce conditional payment methods let you set those rules so shoppers never pick an option that will fail.

Messaging changes what goes into the cart only if shoppers see it before checkout. Use the provider widgets that show the installment amount under the product price and on the cart page. Stick to the provider's approved wording rather than writing your own "0% interest" banner. BNPL promotions are credit advertising, and disclosure rules can apply, so confirm the details with a qualified professional. Each widget also loads third-party scripts onto your pages. Keep a list of what every BNPL plugin loads, and read our PCI DSS 4.0.1 payment page script rules explainer. The tradeoffs in comparing express checkout buttons apply to installment buttons too: every extra button is one more choice at checkout.

Test Refunds on a Live Order First

Refunds are where BNPL setups break. A full refund cancels the shopper's remaining installments only if it reaches the provider. On a plugin that doesn't sync, your books and the shopper's balance will disagree. Partial returns lower the outstanding balance and can shrink or remove later installments. Stripe's docs confirm Klarna supports full and partial refunds, so check the same for each method you enable. Disputes follow the provider's process, or your gateway's on a toggle setup. Expect to be asked for tracking, delivery confirmation and customer messages by a deadline. Read each provider's dispute terms before launch.

If you sell preorders or backordered items, also confirm when each method captures payment and how long an authorization stays valid.

Run this test before real customers see the button:

1. Place a live BNPL order on a low-priced product.
2. Ship it, or mark it shipped if capture happens at fulfillment.
3. Issue a partial refund from WooCommerce admin and confirm it appears in the provider or gateway dashboard.
4. Refund the rest and confirm the order closes cleanly on both sides.
5. Match the payout, fee and refund lines against your accounting.

Start With Your Margin and Your Promo Date

This week, pull last quarter's average order value and gross margin by product category and run the break-even formula for each. Then check whether your WooPayments or Stripe account is on an introductory BNPL rate, and when it ends. If PayPal is already on your checkout, compare its built-in option in our WooCommerce PayPal Payments and Pay Later guide before adding a second installment provider.

BNPL fees apply to a slice of your orders. Card fees apply to most of the rest. If you want a second look at the card side of your online payment processing, MannyPay integrates with WooCommerce and can review your current setup. Request a free quote, and a MannyPay specialist will respond within one business day.

Sources

1. Stripe: Local Payment Methods Pricing
2. Stripe Docs: Afterpay and Clearpay Payments
3. Stripe Docs: Klarna Payments
4. Stripe: Flexible Payment Options With Klarna on Stripe
5. Stripe: Afterpay/Clearpay, an In-Depth Guide
6. Klarna: Pricing for Merchants Located in the United States and Canada (September 2023 annex)
7. Checkout Page: Stripe Fees 2026
8. eSEOspace: WooPayments Explained: Fees, Payouts and Alternatives
9. DevDiggers: Best WooCommerce Buy Now Pay Later Plugins for 2026

IC

About the author

Isabella Cruz

Isabella Cruz is Business Growth & Commerce Editor for Beyond the Swipe, writing for small businesses, restaurants, retailers, entertainment venues and e-commerce sellers.

This article is for general educational purposes and is not legal, tax or financial advice. Card network rules and state laws change; confirm current requirements for your business.