Probably easier than with a person. A company has incorporation documents which exist in an already-verified public registry and have dates and other information.

This particular IDV flow will be used with consumer Claude web accounts only.

https://news.ycombinator.com/item?id=48619003

Doesn't say anything about age.

It does at the end of the article, under 18 will be banned

How does a dark lord born before the beginning of time verify its age?