Glossary: SSL and security
What is a Wildcard SSL Certificate?
An SSL certificate covering a domain's subdomains at one level, such as shop.example.co.uk and blog.example.co.uk.
What it is
A wildcard certificate is issued for a name such as *.example.co.uk. The star stands for any single name at that level, so one certificate covers shop.example.co.uk, blog.example.co.uk and any others you add later.
What it doesn't cover
It only covers one level. A certificate for *.example.co.uk doesn't cover a.b.example.co.uk. Check whether it includes example.co.uk itself, as this can vary.
When it's worth it
It makes sense when you have several subdomains, or add them often, because you only manage one certificate. If you have just one or two sites, separate certificates are usually simpler, and a free certificate may be all you need.
One thing to be careful of
The same private key protects every subdomain, so if it's exposed on one server, all of them are affected.