The bureau has constituted an expert group chaired by former National Statistical Office (NSO) director general A K Sadhu to provide technical guidance on the base-year revision.
A separate standing tripartite committee, comprising representatives of employers, employees and the government, will also advise on the exercise.
The bureau is consulting state governments, Union Territories and other stakeholders on the proposed changes.
The existing CPI-IW series has a base year of 2016 and covers seven sectors — factories, mines, plantations, railways, public motor transport undertakings, electricity generating and distributing establishments, and ports and docks.
The Labour Bureau has begun collecting employment data from state and central government agencies to identify centres for the revised series. The target base year for the new series has not yet been specified.
The ongoing exercise is expected to add the construction sector to the index, taking the number of centres covered from the existing 88 to 130, according to people privy to discussions during consultations on the revision.
The addition of construction has been recommended by the expert group chaired by Sadhu.
The proposed expansion is intended to capture a wider range of occupations, working conditions and geographical areas.
The CPI-IW measures changes in retail prices of goods and services consumed by industrial worker households.
It is used to revise dearness allowance (DA) for central and state government employees and workers in organised-sector establishments, as well as for determining variable DA and revising minimum wages.
It is also used for wage adjustments under agreements and price escalation clauses in business and public works contracts.
The index is released every month by the Labour Bureau, along with the Consumer Price Index for Agricultural Labourers and Rural Labourers (CPI-AL/RL).
The CPI-AL/RL series was revised last year, with the base year updated from 1986-87 to 2019 with effect from June 2025.
The revision expanded its coverage from 20 states to 34 states and Union Territories, and increased the number of sample villages from 600 to 787.
The CPI-IW revision is now the next major base-year updation exercise for the Labour Bureau’s consumer price indices.
The revision will also require fresh data on the spending patterns of working-class households.
The Bureau has asked the NSO to allocate a time slot for conducting the Working-Class Family Income and Expenditure Survey (WCFI&ES).
The survey provides expenditure data used to calculate the weights assigned to different items in the CPI-IW basket, the people said.
Emails sent to the Ministry of Labour and the Labour Bureau did not elicit a response till the time of going to press.
Among other areas being looked into for the revised index are changes in household consumption since the 2016 base year, including the addition of online and over-the-top (OTT) services and other emerging items.
The exercise is also examining alignment of the classification of items with the international Classification of Individual Consumption According to Purpose (COICOP) 2018 standard.
The bureau is also considering greater use of digital tools in price collection, including computer- and mobile application-based collection, geo-tagging and time-stamping of price entries.
Other proposals include examining the feasibility of collecting prices from online markets and e-commerce platforms, and using artificial intelligence (AI)-based analytical tools to detect unusual price movements and inconsistencies in the data.
- CPI-IW revision may expand coverage from 88 to 130 centres
- Construction sector likely to be added to the index
- Seven sectors currently covered; new base year yet to be decided
- New basket may include OTT, online services
- Digital price collection, geo-tagging, AI-based checks under consideration
- Revised index to guide dearness allowance and minimum wages
