Google will require all advertisers to confirm their legal identity in an effort to increase transparency. Since 2018, political advertisers have had to verify who they are, so this is an expansion of that measure.
The company will enforce the rule in the US at first, and it's likely to take a few years before the requirement rolls out worldwide. Google suggests advertisers that in certain categories may be prioritized for the verification process. Those include the promotion of "products, goods, and services" (such as retail, media, tech and travel), "informational, advisory, or educational content"(charitable causes and free financial or health advice, for instance) and ads related to regulated industries, like gambling and healthcare products.