Why can’t I use my email ID as my Apple ID

What happens when you try? Error message(s)?

Apple hasn’t published any guidance for using an address again. Normally, if your e-mail address was associated with an ID in any way, for example as a Notification email address or a Rescue e-mail address, then it can't be reused with another Apple ID for approximately one year. I have also seen posts that stated Apple told them there was a 30 day waiting period before the address could be used again.  You will need to get another e-mail address to use as your Apple ID or you can try waiting 30 days to see if that works.

There have been posts by people who have contacted Apple Support and they were told that if you delete an ID associated with an email address, you can never reuse the email address for an Apple ID.  I have also seen posts that stated Apple told them there was a 30 day waiting period before the address could be used again.You will need to get another e-mail address to use as your Apple ID or you can try waiting 30 days to see if that works.

Correct. All evidence from those who’ve posted about deleting an AppleID indicates a deleted AppleID email address can never again be used with an AppleID in any way.

How to delete your Apple ID account - Apple Support

Note the mention that: “When you delete your Apple ID, Apple makes our best effort to delete all personal data associated with your account. However, we are required to retain past transaction information for financial reporting purposes, and we may be required to retain certain information to comply with a court settlement or other ongoing legal procedure.”

Since the AppleID is identified by the primary email address used, it would seem that email address is kept on record and tied to that limited data Apple is obligated to keep on file. So that email address is then barred from ever being used again with an AppleID.

I went through the process of deleting an old Apple ID with apple support 3 years ago and still can’t use that email address in my Apple ID ! Not even as a rescue email address.