Under Section 13B (2) of Representation of People Act, 1950, BLOs are appointed from amongst the officers of the Govt. /Semi Govt. /Local Bodies. Generally, one BLO is responsible for one part of the electoral roll. From August, 2006 the Commission has decided to introduce the concept of appointing BLOs who would be accountable for ensuring the fidelity of electoral roll
The ECI introduced this new system of appointing BLOs creating a clear line of accountability for preparation of an error-free electoral roll, making the BLOs its custodian at the polling booth level. Previously, voter-identification slips used to be distributed by the contesting candidates of various political parties and that gave scope for complaints. The preparation of accurate electoral rolls and direct distribution of voter identification slip by the BLOs also boosted voter confidence in the credibility of the election process.