Stripe Checkout Auto Tax Calculation Fails with Multiple Payment Methods in Next.js

Below is a summary of the current situation and available options:

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Background

When you offered only the card method, Stripe Checkout would automatically use that for tax calculation. Once you added other payment method options (as radio buttons), no single method was pre‐selected, so the Checkout page wouldn’t supply a payment method parameter (until the customer interacts with the radio buttons). Because the automatic tax calculation now depends on that parameter, the tax amount isn’t computed until later user interaction. This results in an amount mismatch error (“checkout_amount_mismatch”) on the first submission and forces the customer to click through twice.

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Default Payment Method in Hosted Checkout

At this time, Stripe Checkout does not offer an option to pre-select a payment method when using multiple payment methods. In other words, there isn’t a documented parameter in the Checkout Session creation API that lets you set a default payment method to ensure that automatic tax calculation is triggered as soon as the customer enters their address details.

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Alternative Options

1. Using a Custom Checkout UI:
   To control the user experience fully (including setting a default payment method or triggering tax recalculation when address fields change), you might build your own checkout page. This would let you capture address details and automatically send all necessary parameters (including a default payment method) to Stripe when creating the PaymentIntent or Checkout Session.

2. Educate the Customer:
   As a temporary workaround, you could add UI messaging that prompts customers to select a payment method early in the flow. This isn’t ideal from a UX standpoint but may help reduce confusion until a future update.

3. Contact Stripe Support:
   Since this issue directly ties to the way automatic tax calculation currently handles payment methods, you can also reach out to Stripe Support to inquire if there are upcoming improvements or workarounds that would allow setting a default payment method while using multiple payment methods in Checkout.

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Your Checkout Session Object

Your current Checkout Session object looks similar to the following:

JAVASCRIPTCopied
{
  line_items: [],
  mode: 'payment',
  shipping_address_collection: {
      allowed_countries: ['US'],
  },
  customer_creation: 'always',
  phone_number_collection: { enabled: true },
  billing_address_collection: 'required',
  tax_id_collection: { enabled: true },
  allow_promotion_codes: true,
  automatic_tax: { enabled: true },
  success_url: `${getBaseUri()}/stripe-success/{CHECKOUT_SESSION_ID}`,
  cancel_url: `${getBaseUri()}?canceled=true`,
  shipping_options: activeShippingRates.map((item) => {
      return {
        shipping_rate: item.id,
      }
  }),
}

While this setup works well when a single payment method (card) is used, adding multiple payment methods without a default selection causes the observed tax calculation delay.

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Final Note

Currently, using Stripe’s hosted Checkout page with multiple payment methods means you won’t be able to set a default payment method via the API. If a seamless experience is critical, a custom Checkout implementation or reaching out to Stripe Support for further guidance would be the recommended steps.

I hope this helps clarify your options. Let me know if you have further questions about Stripe’s API or Checkout documentation!