As of March 1, 2018, Certification Authorities will cease issuing 3-year SSL certificates for OV and DV validation. Re-issue after February 28, 2018 will be valid for no longer than 27 months, regardless of the original period. If you use certificates issued for 10 years and re-issue them, the CA will be forced to shorten their validity period.
The original three-year OV and DV certificate, issued before March 1, 2018, retains its 39-month validity. Only reissue and duplicate issues will be subject to the reduced maximum validity of the certificate.
When you need to reissue your certificate?
If you run a online business, you are sure to use Google AdWords. Perhaps this is one of the main traffic sources on your site, so the last message you want to see is "Your account has been suspended ...". And yet, you can expect it if your site is not SSL-secured.
Starting 1st of August 2016, Comodo and DomenySSL will no longer offer SGC variants of certificates. As your account has a valid SGC certificate which will be up for renewal in the future, the company has prepared a list of recommended alternatives.
Thawte is only one of the few vendors outside of the United States. As the main competitor of American vendors quickly gained a 40 % share of the market SSL certificates.