Update update-billing-info.mdx

Referring to the new article in context

Author: simon-says

src/content/docs/billing/update-billing-info.mdx

@@ -11,6 +11,10 @@ If Cloudflare is unable to process your payment, review [Troubleshooting failed
 
 ## Update payment methods
 
+:::warn
+If you already have 2 payment methods, you may not be able to update an existing method. Refer to [Troubleshoot updating payment methods](/billing/troubleshoot-updating-payment-methods) for further details.
+:::
+
 1. Log in to the [Cloudflare dashboard](https://dash.cloudflare.com) and select your account.
 2. Go to **Manage account** > **Billing**.
 3. Select **Payment**.