The payment amount input was capped at BalanceDue (e.g. $5.00) but the
customer was being charged TotalWithSurcharge (e.g. $5.15), causing
validation to reject any attempt to pay the correct total amount.
Input now defaults to and accepts up to TotalWithSurcharge. On submit,
the JS back-calculates the base amount before sending to the server so
the server-side surcharge addition produces the same PaymentIntent total
that the Stripe Elements were initialized with — eliminating the
amount-mismatch error from Stripe on confirmation.
Also calls elements.update() when the amount changes so partial payments
don't cause an Elements/PaymentIntent amount mismatch.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
spouliot
4ac62551f4