How to fix ssl cert invalid on BigCommerce

Steps for BigCommerce

1. BigCommerce auto-provisions free SSL certificates for all storefronts on bigcommerce.com subdomains and for custom domains connected through the control panel.
2. Go to Store Setup → Domain Settings. Confirm your custom domain is correctly pointed to BigCommerce (DNS CNAME to stores.yourstore.bcapp.net or the value BigCommerce specifies).
3. If the SSL status shows an error, click 'SSL Settings' next to your domain and select 'Let BigCommerce manage my SSL certificate'. BigCommerce will provision a new Let's Encrypt certificate automatically.
4. If you are using Cloudflare or another proxy in front of BigCommerce, ensure the SSL mode in Cloudflare is set to 'Full (Strict)' and that a valid certificate is also installed at the BigCommerce origin.
5. Contact BigCommerce Support if the certificate does not provision within 24 hours.

What is ssl cert invalid?

Every website served over HTTPS needs an SSL/TLS certificate issued by a trusted Certificate Authority (CA). That certificate must list the exact domain name (or a wildcard that covers it) your visitors use to reach your store. A "hostname mismatch" error means the certificate installed on your server was issued for a *different* domain — for example, it covers `www.example.com` but your store is accessed at `example.com`, or the certificate belongs to a completely different domain altogether. Browsers check this match every time someone loads your site; if it fails, they show a full-screen warning and refuse to complete the connection.

A certificate hostname mismatch is one of the most damaging trust failures an online store can have. Browsers (Chrome, Firefox, Safari, Edge) display a red "Your connection is not private" warning that blocks visitors before they ever see your store — most users immediately leave and never return, costing you sales directly. Google treats HTTPS as a ranking signal and may demote or de-index pages that cannot be loaded securely, reducing your organic traffic. From a legal and compliance perspective, payment card industry (PCI-DSS) rules require that cardholder data be encrypted with a valid certificate; a mismatch means you are technically non-compliant and could face fines or lose the ability to accept cards. Under OWASP's A02:2021 Cryptographic Failures, an invalid certificate is classified as a critical security vulnerability because it leaves all data exchanged between your customers and your store potentially exposed to interception.

See the complete Ssl cert invalid guide for every platform and the full background.