Each person can only have one adsense account, may I ask google company by what way to determine whether a person has only one adsense account?

Google uses a variety of methods to ensure that each individual adheres to the policy of having only one AdSense account. While the exact details of their approach are not publicly disclosed, some of the general measures they might use include:

**Personal Information Verification**: Google may require personal identification information such as name, address, phone number, and tax identification number to verify the identity of the account holder.

**IP Address Tracking**: Google may track the IP addresses used to create and manage AdSense accounts. If multiple accounts are created from the same IP address, it could raise flags.

**Cookies and Device Fingerprinting**: Technologies like cookies and device fingerprinting can help identify unique devices and browser configurations to monitor for multiple accounts.

**Banking Information**: When setting up a payment method, Google collects banking information that can be tied to a specific individual. If multiple accounts use the same banking details, it could indicate a violation of their policy.

**Account Linking**: Google may also use algorithms to detect if accounts are linked through shared data or user behavior, potentially indicating that multiple accounts are associated with the same person.

**Reporting and Audits**: Users can report suspicious activities, and Google may conduct audits to investigate accounts that appear to violate their policies.

If you need specific guidance on Google AdSense policies or have concerns about your account, it might be best to consult the official Google AdSense Help Center or contact their support directly.