Google Ranking Factor – Change of Address
If you are considering changing your domain name, to preserve the maximum amount of rank, follow the Google Change of Address process in Google Search Console. This will preserve nearly 100% of your pagerank, and in my experience the changeover period is around 14 days – very fast by regular indexing standards as they can take 3 months or more.
If changing the domain name without following this process and also failing to set 301 redirects, all connection to backlinks, social shares and current page ranking will be lost.
Try to avoid a change of address if you can, but if you must, make sure you follow the correct process.
This is best handled by an SEO professional as it involves strict process in GSC and also may require setting dynamic URL re-writers in an .htaccess file.