Verify secure domain ownership & control
Checking domain ownership details, such as registrant name (the official owner of the site, on paper, unless changed) and registrar website login details (which enable custodians to change everything including the registrant name and even the registrar) is well worth doing for any serious client as part of a detailed technical SEO audit, as if there’s any debate, these details will be critical in proving ownership and ultimate control of this site which of course can have as big an effect on SEO as anything, and as the digital specialist, your client really depends on you to keep them aware of the significance of such things. And it only takes a minute to ask the client a question like “Do you have access to the registrar, and should X be the official registrant name?” – once you’ve asked them you’ve done your due diligence and can proceed with your audit with or without an answer to the question.
If you’re using domain privacy services, those services could in theory hijack the domain, as you’re officially saying they are the real owner, so it is important to check whether or not they are a trustworthy organisation – for example are they owned/provided by an ICANN-accredited registrar? This is a useful check, as it guarantees a level of security. If they are ICANN-accredited, then any disputes over domain ownership must follow ICANN’s clearly defined procedures which are quite fair & just, else the naughty registrar risks losing its accreditation and can potentially get sued after that, plus ownership of all domains can ultimately be seized by ICANN if deemed necessary.
Consider the expiry date
It’s also worth noting domain expiry date, not just for security but because Google also slightly trusts longer-registered domains more, as spammers & fraudsters tend to register for single years (expecting their domain to be banned, blacklisted, etc, thus saving money by not registering for unnecessary extra years). There has been evidence suggesting it is one of the many factors considered in ranking any given domain, so it’s worth having on any audit report even if you don’t intend to take measures to extend the registration period of the domain, just because it’s a noteworthy factor worth considering at some point.