The Unique Identification Authority of India (UIDAI) is the statutory body established under the Aadhaar Act 2016 that issues 12-digit Aadhaar numbers to Indian residents. UIDAI provides multiple verification routes: Aadhaar number validation (checks the Verhoeff checksum without revealing demographic data), online e-KYC for authorised entities under the Authentication User Agency framework, QR-code verification on e-Aadhaar PDFs, and offline XML verification for service providers who don't have internet access. The myAadhaar portal lets residents check authentication history, lock biometrics, and update demographic data online. All Aadhaar verification respects the Aadhaar (Authentication) Regulations 2016 and requires explicit consent of the resident.