You can search (Google) all-day-long and you will not find a definitive answer to this question.
Why is that?
For clarity, here is the closest thing you’ll find on the topic https://support.google.com/webmasters/answer/34592?hl=en
Note, we are not talking about Subdomains! The question is multiple domains.
We are talking about multiple domains aren’t we? Exactly!
I have been “doing this stuff” since Google was birthed (or became better than Altavista) @ 2001. I have seen all the evolution of methods Google creates to do things with Google. These “things” I’ll call “methods”. They are simply ways to communicate with Google
so they can do what they want to do; bigger, faster, better. These methods are called SEO (or “White-Hat SEO” that is).
So there are millions of people (just like you) doing their own SEO. You spend hours reading Google support pages like most people read the newspaper. You participate in forums, ask questions, write about your opinions and experiences. All that gets indexed by Google.
Then how can a question like this remain ambiguous?
Exactly! Now here is where the developer says, “I don’t understand?”. The marketing person says, “But of course! That’s marketing”. The business person says, “Of course! That’s the nature of proprietary information”.
I’m going to answer this question based on experience alone.
- Question: Can I use one Google Search Console for multiple domains?
- Answer: Its probably not a good idea.
- Question: That’s no answer. OK! Why should I NOT use one Google Search Console for multiple domains?
- Answer: Because Google likes Accounts linked to websites. ( And so do you because it provides more accurate telemetry in your analytics reporting ).
An ACCOUNT is a gmail login. A website is a PROPERTY of the ACCOUNT.
- Question: I don’t get what that has to do with setting up multiple Domains in Google Search Console?
- Answer: Because Google links Services (like Analytics) with Search Console, with Adwords, with GMB (Google My Business – God awful name that it is), and Adsense, etc.
Given all that linking between SERVICES, why do you think its a good idea to add to the complexity by adding multiple domains (Properties) to one Search Console (Account)?
- You are not supposed to ask US questions! You are just blowing smoke with this “Services linked to Properties, linked to Accounts”. What’s next in your complexity lesson? Worm-holes?
I have found only by relative search rank performance – there is no absolute benchmark I can offer – that keeping 1 Google Account (gmail) dedicated to 1 Domain (website), yields much better search rank performance ( also mistakenly called SEO. re “My SEO is now much better because I...” Sounds like a health problem to me ).
- Question: What else? Is that all that is floating around in your pea-sized brain?
- Answer: No. Keeping 1 Google Account (gmail) dedicated to 1 Domain (website) also cuts down on management headaches, because Google gives you all the methods you need to setup your many Account/Domains in an easy-to-manage MCC, ( …wait for it…)
proving that Google is very aware of the difficulties in adhering to all these ever-changing “methods” they create for you, whether you can find it documented online or not.