Starting next March 18, another 850 households will be surveyed for the tenth Household Expenditure Survey (HES) conducted by the Singapore Department of Statistics (DOS). These households will make up the 13th and 14th groups in the year-long survey.

Conducted once every five years, the survey collects up-to-date information on households' expenditure for the compilation of the Consumer Price Index (CPI).

The survey groups will cover households in Bukit Timah, Hougang, Macpherson, Newton, Orchard, Potong Pasir, Sembawang and Simei.

Survey officers carrying identification cards will visit the selected households, which will be notified about the visit in advance. Households who wish to verify the identity of the survey officers or reschedule their appointment may call 1800-888-1213 from 8.30 am to 10pm.

All information supplied by households will be kept in confidence in accordance with the Statistics Act, said the Department in a statement on Monday.

The tenth survey is conducted between October 2012 and September 2013. It covers 11,000 households, which are divided into 26 groups with each group being surveyed for a period of two weeks.