If age isn't verified, Google will turn on YouTube Digital Wellbeing tools (which include things like bedtime and break reminders and safeguards on content recommendations), disable Timeline in Maps, turn off personalized advertising, and prevent the user from accessing Google Play apps intended for adults.

If Google’s AI gets it wrong and flags an adult as underage, you can fix it by verifying with a credit card or government ID. But if the system already sees you as over 18 based on your activity, you’ll just get the regular Google setup.