Insert Person Account through API
When the Person Account feature is enabled in a Salesforce instance, a new Account Record Type is introduced. And a common way to insert a Person Account via API (i.e. Data Loader) is to define the Last Name and the Person Account Record Type ID which is different from the Business Account Record Type ID.
But, Salesforce is smart enough to take in alternative way in recognizing a person account by only mapping the Last Name.
The Last Name field is acting as a command to differentiate person account with business account type because if it is a business account, the company name will contain no first or last name. Therefore, to insert a person account, apart from mapping other related fields, remember to map the Last Name field to tell the API that the data we are inserting is a personal account record.