# What is SSL expiry?

> SSL expiry is when a website's security certificate reaches its end date without being renewed, causing browsers to show a full-page security warning.

- Source: https://nerdsharks.com/glossary/ssl-expiry
- Publisher: Nerdsharks (Exeter, Devon, UK)
- Updated: 2026-09-26

Also called: expired SSL, certificate expiry, NET::ERR_CERT_DATE_INVALID.

Every SSL certificate has an expiry date, and the maximum allowed lifespan is being shortened in stages by the browser and certificate industry. Free certificates such as Let's Encrypt's already last only a few months, so they must be renewed regularly.

When one expires, browsers do not just show a small warning; they typically block the page with a large ‘Your connection is not private’ message. Most visitors will not click past it.

Good hosting renews certificates automatically. Problems usually come from manual setups, a card that failed on renewal, or DNS changes that stop the automatic renewal working.

## Why it matters for a small business

An expired certificate makes your website look dangerous overnight. Customers who see the warning will not ring you; they will go back and pick someone else. Automatic renewal, plus someone watching for failures, prevents it.

**Example:** On a Monday morning a landscaper's site suddenly shows a red security warning. The certificate was set up manually three months earlier and nobody renewed it.