Director Identification Number (DIN) is a unique identification number for existing or prospective company directors in India. It is a mandatory requirement introduced by the Ministry of Corporate Affairs for e-filing of company documents. Individuals must apply for a DIN by submitting identity and residence proof documents, and can check the status of their application online. A single DIN is sufficient irrespective of the number of directorships held. Key benefits of DIN include easier detection of director offences and helping investors make informed decisions.