Following last week’s release of the first prerelease, v3.0.0-rc2 of the Stripe gateway for SimpleCart is now available in the pre-releases channel.
In rc2 we’ve added additional client-side checks to prevent submitting the payment if the customer hasn’t entered their billing information yet. This should in most standard implementations prevent a payment from being charged but then failing due to server-side validation running later.
If you have additional validations in the checkout form, make sure to use HTML5 validation markup on those fields so the gateway can automatically check those, too.