PayPal, Inc. # Street: 2211 N 1st St # Locality: San Jose # State: California # Postal Code: 95131-2021 # Registered: Delaware, US
And we could include other information if we needed.
For PayPal this number is 3014267 and it'll be their registration number with the state of Delaware.
The EV rules require a CA to figure out if there is such a number and if so fill it in on the certificate. If there is no number, they're supposed to write something else (a registration date maybe? I don't remember)
(Sometimes a country has some companies that are so crazy old they pre-date the idea of registering companies, or turn out not to exist in their company register because the country created them by passing a law instead of formally registering them, or whatever, and these don't have serial numbers, e.g. I wouldn't be surprised if the Bank of England has no registered company number)