Okay, I guess I don't know what this is: "THE Accountant would now like to consolidate both clients under one single Intuit account (Realm)."

They already stated they have the one log in.

I have one Intuit ID. I log into QBO to any one company data file (including my own, a test file); I log into QBOA to see a multiple client listings (multiple test/sample files, really), which also is where I can add QBO accounts to that listing (I could add real QBO customers, for example). From there I log into, or select to switch to, the PTO interface, which shows those QBO accounts I have "linked over" (I don't know how else to state it) and now I also see the far right would allow me to create tax returns for any of them.

Now, for my Intuit ID products, that is a bit of a mess when I log into "CAMPS." Top right I still see 3 to select from, and used to see 5 "Company names" because I used to have multiple Intuit IDs (testing used to require us to create new Intuit accounts) and I finally got them merged into this one. I also see my products are scattered across 2 of those 3 accounts at the top. This top right menu allows you to Transfer to Admin another username, though, and I did that when I left one job; transferred them to the new person. For my school, the person adding me as a user no longer existed and there is no provision to remove yourself except if you are the Admin; Intuit had to help me do that part.