when the AI can, without prompting...
open its own bank accounts
figure out how to dodge/minimise taxation of its profits
negotiate licensing terms for its patents
sue for alleged violations, and win
set up and run manufacturing, distribution and sales
handle the hr issues
bribe politicians
take over competitors
do charitable good, or fund demagogues
decide what else to spend its money on, perhaps amass a fine art collection, or a superyacht
it'll have shown it's enough of a person to hold a patent
otherwise it's just a piece of design/optimisation software created by humans, and has no more rights than a toaster