NEW DELHI: The pre-test for houselisting phase of Census 2027 will be undertaken from Nov 10 to Nov 30, 2025 in selected sample areas spread across all states and Union territories, the Centre announced in a notification issued on Thursday.The pre-test — meant to test efficacy of the census questionnaire, proposed data collection methods including via the digital mode and other logistics – will allow an option of self-enumeration to the respondents between Nov 1 and Nov 7, 2025.The pre-test will cover only the houselisting and housing phase of the upcoming census exercise — which gets underway in April 1, 2026 — as per the notification issued by MHA in exercise of the powers conferred by Section 17A of the Census Act, 1948, read with rule 6D of the Census Rules, 1990.The home ministry had on June 16, 2025, notified its intent to conduct Census 2027 — the first ever to be done in the digital mode — with March 1, 2027, as the reference date. For the UT of Ladakh and snow-bound areas of J&K, Himachal Pradesh and Uttarakhand, the reference date would be advanced by six months, to 00.00 hours of the first day of October 2026.According to sources, Census 2027 – which is likely to put out final population data by 2027-end, setting the stage for delimitation and, based on it, implementation of women’s quota in legislatures by the 2029 general election and, eventually, increase in strength of the Lok Sabha and state assemblies – is likely to replicate the schedule of past decennial exercises. It will be held in two phases – housing listing operations, likely between April 1, 2026, and Sept 2026, followed by population enumeration from Feb 9 to 28, 2027.Caste enumeration – a first since the 1931 Census – is likely to be done in the second phase of population enumeration. Unlike the 2011 exercises, no parallel updation of the Narional Population Register (NPR) is planned along with Census 2027.A four-day, intensive training of lead trainers for Census 2027 pre-test was conducted last week at the Registrar General of India and Census Commissioner’s office here on Friday. These lead trainers are now training the enumerators in the states/Union territories, following which the pre-test will be taken up in the field. A pre-test was last conducted for Census 2021 — before the exercise had to be put on hold on account of the Covid pandemic — in August-September 2019. However, since the Census methods have since been updated — with major improvements in applications to capture data and options of self-enumeration for both the houselisting and population enumeration phase — a fresh pre-test was deemed necessary. No fresh questionnaire has been notified yet for Census 2027; in all probability, there shall be no change in the data fields to be captured in the houselisting phase.Refresher training in the coming days will reorient the 34 lakh enumerators and supervisors and 1.3 lakh Census functionaries in the use of Census apps and the Census management and monitoring system.