India's death toll in 2021 during the COVID-19 pandemic: insights from delayed official civil registration data

India released its 2021 official death registration data in May 2025, showing a dramatic undercount of reported COVID-19 mortality in 2021 - a year that included the lethal second wave from the Delta variant in April to June 2021. The civil registration system (CRS) documented 10.2 million deaths in 2021 - a 26% increase from 2020 - compared to only 335 004 reported COVID-19 deaths. We calculated excess deaths as the difference between observed deaths and expected deaths had pre-pandemic mortality trends continued. Our analysis reveals India experienced approximately 2.4 million excess deaths in 2021, representing a 7.2× undercount compared to reported COVID-19 deaths. This aligns with the estimates derived from several epidemiological models during and after the pandemic, indicating excess-to-reported COVID-19 death ratios ranging from 4.4× to 11.9×. State-level analyses revealed considerable variation in reporting fidelity, with excess-to-COVID-19 death ratios ranging from under 2× in Kerala and Goa to over 40 in Gujarat. Limited disaggregated data showed excess death rates were substantially higher in men than women (2.2 vs. 1.3 per 1000 population), and in urban than rural areas (2.3 vs. 1.4 per 1000 population). Since the CRS data are incomplete in terms of age-stratified deaths, the proportional allocation of deaths by age according to external sources suggests excess death rates were higher in the 65 and older age group than in the population under 65 (14.1 vs. 0.9 per 1000 population). The four-year data delay and systematic underreporting underscore urgent needs for modernising India's surveillance system during acute phases of the pandemic and restructuring the official vital registration systems through protocol standardisation, real-time linkages, and infrastructure investments. Robust mortality tracking strengthens crisis preparedness and broader public health response.