Why SSL Certificate Validity Periods Matter: Expiration Explained

When you scan a website with GuardSSL, you'll see two important dates: Valid From and Expires On. These dates define when your certificate is active. But why do certificates have expiration dates? And what happens when they expire?

Why Do SSL Certificates Expire?

You might wonder: if getting a certificate is such a hassle, why not make it last forever?

Security Reasons

This is the primary factor. Cryptography and technology evolve constantly:

• Encryption algorithms considered secure today might be found vulnerable in a few years
• Private keys could be leaked without your knowledge
• Website ownership may have changed
• Regular rotation limits the window of opportunity for key compromise

Just like you should change your passwords periodically, certificates need regular updates too.

Encouraging Adoption of New Standards

If certificates never expired, many websites would still run decade-old configurations. Expiration forces site administrators to periodically review and update their security settings.

How Long Do Certificates Last?

Different certificate types have different validity periods:

Certificate Type	Typical Validity	Notes
Let's Encrypt	90 days	Free, requires auto-renewal
Commercial DV	1 year	Most paid certificates
Commercial OV/EV	1-2 years	Enterprise certificates

Industry Trend: Since 2020, all public CAs limit certificates to a maximum of 1 year (down from 2 years). This change was driven by Apple, Google, and Mozilla. More frequent updates mean better security.

What Happens When Your Certificate Expires?

What Users See

When an SSL certificate expires, visitors encounter a scary warning page:

• Chrome: "Your connection is not private"
• Firefox: "Warning: Potential Security Risk Ahead"
• Safari: "This Connection Is Not Private"

Most users will leave immediately rather than click "Advanced" to proceed.

Impact on Your Business

• Traffic plummets: Visitors are scared away
• SEO suffers: Google doesn't like insecure sites
• Trust erosion: Users may think you've been hacked
• Revenue loss: E-commerce sites lose money every minute
• Brand damage: Looks unprofessional

A Real-World Cautionary Tale

In 2020, a major company experienced hours of downtime because their certificate expired. The cause? Someone ignored a calendar reminder.

This happens more often than you'd think. Managing multiple domains makes it especially easy to miss deadlines—who can remember 20 different dates?

How to Prevent Certificate Expiration

1. Use Auto-Renewal

If you're using Let's Encrypt with Certbot, set up automatic renewal:

certbot renew --dry-run

Most modern hosting platforms (Vercel, Netlify, Cloudflare, etc.) handle this automatically.

2. Set Up Monitoring Alerts

This is exactly what GuardSSL was built for!

• Get notifications 30 days, 7 days, and 1 day before expiration
• Receive alerts via Email, Slack, Discord, and more
• Manage all your domains in one dashboard

3. Calendar Reminders (Backup)

For small portfolios:

• Set phone reminders 30 days before expiration
• Not the most reliable method, but better than nothing

4. Verify Auto-Renewal Actually Works

Even with automation in place, periodically verify:

• Has DNS configuration changed?
• Are server permissions still correct?
• Is the renewal script still running?

Understanding Valid From and Expires On

In GuardSSL results:

• Valid From: When the certificate becomes active
• Expires On: When the certificate becomes invalid
• Days Left:
  • 🟢 Green (> 30 days): Safe
  • 🟡 Yellow (< 30 days): Attention needed
  • 🔴 Red (< 0 days): Already expired!

Key Takeaways

• SSL certificates expire for security reasons
• Industry standard is now maximum 1 year (Let's Encrypt uses 90 days)
• Expired certificates cause lost traffic and damaged SEO
• Use auto-renewal + monitoring alerts for double protection
• GuardSSL helps you get notified before certificates expire

Never let an expired certificate be the reason your website goes down.