What type of number is required before starting or applying for a job in the U.S.?

Before starting or applying for a job in the U.S., a Social Security number is required. This number serves as a unique identifier for individuals within the Social Security Administration system and is primarily used for tracking earnings and benefits. Employers use the Social Security number to report an employee's income to the IRS and to verify the individual's eligibility to work in the country.

The presence of a Social Security number is essential not only for tax purposes but also for various legal and administrative functions related to employment. While tax identification numbers and license numbers may be necessary for specific professions or for tax purposes, they are not universally required for all jobs. An employee identification number is typically assigned by an employer for internal tracking purposes but does not replace the need for a Social Security number when it comes to employment eligibility and federal requirements.