Domain names play an important role in your search engine optimisation, and there are times where you’ll want to change that domain name to reflect the direction you’re going in.
While that is not a bad thing to do, dropping the original domain name is. Domain names hold history, so all of the search engine data that has been indexed over the timespan that your website was live on the original domain name is actually associated with that domain. Dropping this domain name can ultimately be disastrous for your rankings, as any indexed pages will suddenly get broken links.
What you’ll need to do is make sure the domain name is renewed for a good number of years, and just add a permanent 301 redirect on that domain name to ensure that all traffic ends up forwarding on to the new domain so you don’t drop any customers.
The easiest way to do these is to set up automatic renewals on your domain name through your registrar control panel, and then read by guide on how to set up 301 redirects and choose the option to redirect the whole domain rather than just a single URL.