That’s my rule of thumb. If you want to know why, when there are exceptions, and how to best manage multiple domains, then you should read this article.
Hosting companies are quick to sell you on the idea of hosting multiple domains on a single account. And webmasters are quick to do the math: $10 per month for 5 websites is cheaper than 5 x $10 per month. Well, you should know that there is a danger in this kind of thinking.
The way multiple domains work is they’re in separate folders within the root directory of your hosting account. And that means if a hacker gets into your account, they can access all of those folders. All your sites can be compromised at a single stroke. So all what hacker need is just an access to one of your websites.
If each domain is in a separate hosting account, you’ve isolated the individual sites. Assuming that you’ve got strong passwords on each account, that’s a lot of extra work for the hackers to do the damage they could do in a single account with multiple domains. This is why we at Siteguarding never keep multiple domains on the same hosting account. We always create a separate hosting account for each your website.
Some will argue that simply having good backups is enough and if your site gets hacked you can just restore all the domains with the backup. But most hacking isn’t about crashing sites – it’s about using sites to generate fake pages to scam search engines or to scrape data from your files and visitors or to send out spam emails. All of which can be happening without you knowing. Backups are only of use once you find out the hack has taken place, which may be long after the damage is done.
Others will argue that it’s easier to maintain multiple domains from a single account, but really, how often do you need to access your hosting account? Creating or deleting email account is probably the most common use, and for most small businesses, that doesn’t happen very often. It may take a little extra time and organization to maintain separate hosting accounts, but again, it’s very little compared to the danger of exposing multiple sites to a single hack.