Applicants can complete the registration online, and in some cases, there will be in-person interviews at the Tax Administration Service (SAT). For individual residents with a Unique Population Registry Code (CURP), the process is fairly straightforward, involving the electronic registration form on the SAT website. Minors require their parents to schedule an appointment with the SAT and provide an array of documentation such as birth certificates and identification. Those aged 16 and above must register in person and present a special salary declaration.