How EVMs and VVPAT work in Indian elections
India has voted on Electronic Voting Machines in every Lok Sabha election since 2004. Here is what the machine is made of, what safeguards the Election Commission describes, and how it came into use.
By the Janadesh Online editorial team. Facts last checked against the sources below on 25 September 2026.
The three units
- Voting compartmentBallot Unit
A button beside each candidate's name and symbol. You press yours.
- With the presiding officerControl Unit
Stores the votes and, at counting, displays the result.
- Beside the Ballot UnitVVPAT
Prints a paper slip of your choice, shows it for 7 seconds, then drops it in a sealed box.
The machines are stand-alone. According to the Election Commission they are not networked, and they run on power packs supplied by the manufacturers (7.5 volts for the EVM and 22.5 volts for the VVPAT) rather than mains electricity.
Capacity
- 16candidates per Ballot Unit, NOTA included
- 24Ballot Units that can link to one Control Unit
- 384candidates the latest machines can handle
- 2,000votes a machine can record, generally used for about 1,500
Safeguards the Election Commission describes
- Built to resist tampering
One-Time Programmable microcontrollers, so the program cannot be rewritten, and an Unauthorised Access Detection Module.
- First Level Checking
Every machine is checked by engineers of the manufacturers, BEL and ECIL, in front of representatives of recognised political parties.
- Higher mock poll
During First Level Checking, a mock poll with a higher number of votes is run on 5% of randomly selected machines.
- Two-stage randomisation
Machines are allotted first to assembly constituencies, then to polling stations.
- Mock poll on polling day
At least 50 votes are cast at every polling station before the real voting starts.
These are the Commission's own descriptions of its procedures. Debates about EVMs exist, and the Supreme Court has ruled on them; this page does not take a side, it records what the official procedure is. See how the counting and VVPAT verification work.
How EVMs came into use
- 1977
The concept is first taken up. A prototype was shown on 6 August 1980.
- 1982-83
First trial use, at 50 polling stations of the Parur assembly constituency in Kerala.
- 15 Mar 1989
After the Supreme Court halted use, the Representation of the People Act amendment takes effect.
- 1998-99
Further trials, including 45 parliamentary constituencies in 1999.
- Feb 2000
45 assembly constituencies in Haryana.
- May 2001
All assembly constituencies in Tamil Nadu, Kerala, Puducherry and West Bengal.
- 2004
All 543 Lok Sabha constituencies, with more than a million EVMs.
- 14 Aug 2013
Rules amended to allow VVPAT, first used at the bye-election in the 51-Noksen constituency of Nagaland.
Turnout in each election since 1962 is in the turnout records, and every general election result is in the Lok Sabha archive.
Frequently asked questions
Are EVMs connected to the internet?
According to the Election Commission the machines are stand-alone and not networked. They run on power packs, not mains electricity.
How many candidates can one EVM handle?
Each Ballot Unit carries 16 candidates including NOTA, and up to 24 Ballot Units can be linked to a Control Unit, for a maximum of 384 candidates on the latest machines.
How many votes can a machine record?
At most 2,000, though it is generally used for about 1,500 voters.
What is a mock poll?
A trial vote run before real polling. At least 50 votes are cast at every polling station before the actual poll, and a higher mock poll is run on 5% of randomly selected machines during First Level Checking.
When were EVMs first used in India?
On a trial basis in 1982-83 at 50 polling stations of the Parur constituency in Kerala. They were used in all 543 Lok Sabha constituencies in 2004.
What is VVPAT?
Voter Verifiable Paper Audit Trail: a unit that prints a slip with the candidate's serial number, name and symbol, visible for 7 seconds before it falls into a sealed box.
Sources
Janadesh Online is independent and not affiliated with the Election Commission of India. Rules and procedures can change between elections; the Commission’s own notices are the authority. Spotted an error? Tell us on the contact page.
