# Why are payments failing in Stripe?

1. Check the Common Error Messages below to ensure your customer is using the right checkout flow.
2. Ensure email addresses do not include unnecessary capitalizations, such as `123456789@QQ.com`. The proper input should be `123456789@qq.com`. Additionally, some email addresses may be marked as spam or fraud, so advise customers who continuously run into this issue to try using a different email address. 

{% content-ref url="../common-error-messages" %}
[common-error-messages](https://docs.chinapaymentsplugin.com/common-error-messages)
{% endcontent-ref %}