India will conduct the Census 2027 starting with a fully digital self‑enumeration portal on 1 April 2026 . The exercise will be carried out by the Office of the Registrar General and Census Commissioner using mobile applications . Key Developments Self‑enumeration portal opens on 1 April 2026 and runs for staggered periods across States and Union Territories. Citizens can fill the census schedule in any of the 16 official languages. Enumerators will verify the submitted data during the door‑to‑door phase and integrate it into the final database. The first phase will ask 33 questions ; the caste‑related second phase is slated for February 2027 . Important Facts Self‑enumeration steps: login with mobile number → locate address on map → fill household details → submit → receive a unique Self‑Enumeration ID → present ID to the enumerator. State‑wise self‑enumeration windows (e.g., Andaman & Nicobar, Goa, Karnataka: 1‑15 April 2026 ; Kerala, Nagaland: 16‑30 June 2026 ; West Bengal: dates pending). The census is a decennial census , not a quinquennial exercise. COVID‑19 delayed the 2021 census; the 2027 cycle is fully digital to accelerate data processing, with most datasets expected by the end of 2027 . UPSC Relevance The census underpins demographic analysis, resource allocation, and policy formulation—core topics for GS‑1 (Demography) and GS‑3 (Economy & Statistics) . Understanding the shift to digital data collection and self‑enumeration helps answer questions on governance reforms, use of technology in public administration, and challenges of large‑scale statistical exercises. Way Forward Aspirants should track the self‑enumeration schedule for their respective State/Union Territory, familiarize themselves with the 33‑question first phase, and study the role of the Union Territory and State governments in facilitating the census. Monitoring the rollout will also provide insights into digital governance initiatives and their impact on data‑driven policymaking.