Wildcard SSL certificates allow you to secure multiple sub-domains of a single domain instead of requiring a separate certificate for each one.

These certificates are issued for *.yourdomainname.co.uk and can be used in the following ways:

It will produce a yellow lock on the address bar to show users that their data is being encrypted and kept private.

SSL Certificate Name
 
SSL Brand
 
Warranty
 
Validation Type
 
Price
From*
Comodo Positive Wildcard
Secures multiple subdomains of a single domain (Includes www. version of domain as well)
Available for 1,2 & 3 years
Comodo $10,000.00 Domain £57.65 More Info
Comodo Essential Wildcard
Secures multiple subdomains of a single domain (Includes www. version of domain as well)
Available for 1,2 & 3 years
Comodo $10,000.00 Domain £59.98 More Info
RapidSSL Wildcard
Secures multiple subdomains of a single domain (Includes www. version of domain as well)
Available for 1,2 & 3 years
RapidSSL $5,000.00 Domain £66.65 More Info
Comodo Premium Wildcard
Secures multiple subdomains of a single domain (Includes www. version of domain as well)
Available for 1,2 & 3 years
Comodo $250,000.00 Business £106.32 More Info
GeoTrust True BusinessID Wildcard
Secures multiple subdomains of a single domain
Available for 1,2 & 3 years
GeoTrust $10,000.00 Business £206.65 More Info