How Are Votes Counted and Audited? | How It Works

What is the short answer?

When the polls close, election staff must turn marked ballots, or machine records, into one total that losing candidates can trust. First they reconcile: the ballots in each box must match the number handed out. Then the votes are counted by hand, by scanners or by electronic machines.

Candidates' agents watch hand counts. A close result can lead to a recount. Where a paper record exists, a post-election audit compares a random sample of paper ballots with the machine count.

Definition: A risk-limiting audit checks a random sample of paper ballots against the reported result, adding ballots until the evidence that the reported winner really won is strong enough. If it never is, the audit becomes a full hand count. The risk limit is the largest chance that a wrong result survives.

What happens to paper ballots after the polls close?

A UK parliamentary count shows the hand-count method. At each polling station, the presiding officer completes a ballot paper account, a record of the ballot papers issued, spoilt and left unused. Sealed boxes then go to a central count.

The first stage is verification. Staff count the papers in each box. The total should match the number the presiding officer recorded as issued. If not, staff recount until they reach the same number twice in a row.

Only then are the votes counted. Papers are sorted by candidate into bundles of 50, and the totals must agree with the verified figure. Counting agents for each candidate watch the sorting and checking.

A paper without a clear mark is set aside as doubtful. The returning officer rules on it in front of the candidates or their election agents, and records any objections.

How do scanners and voting machines count votes?

An optical scanner reads the marks on paper ballots and adds them up. Many also store a cast vote record, the machine's reading of each ballot. The paper stays behind, so people can check the machine against it later. Colorado's audits work this way.

A direct-recording electronic machine stores each vote straight into its memory. Without paper, the only record is the one the machine made.

Some machines add a voter verifiable paper audit trail (VVPAT): a printed slip the voter can see but not touch, which falls into a sealed box. That slip is a second record, made as the voter watches, that can be counted by hand.

When does a contest get a recount?

A recount counts the same ballots again. Rules for calling one differ by country.

In the United Kingdom, after the returning officer shares the provisional result, a candidate or election agent can ask for a recount. The officer can refuse a request he or she thinks unreasonable, and that decision is final.

Many US states use numerical thresholds. Under Florida's 2026 statutes, a contest decided by half a percent or less of the votes cast must go through the counting machines again, unless the losing candidate waives it in writing. At a quarter of a percent or less, the overvotes and undervotes are recounted by hand.

An overvote marks too many choices; an undervote shows no choice a machine could read. A recount cannot show that every ballot reached the count safely.

What is a risk-limiting audit, and how does Colorado run one?

A risk-limiting audit checks only as many ballots as it needs. Statisticians define it as an audit with a large chance, fixed in advance, of leading to a full hand count whenever a full count would show a different winner. It depends on a trustworthy paper record.

Colorado's legislature began requiring these audits in 2009, and the first statewide audit followed the 2017 coordinated election. Its counties run ballot comparison audits: software picks ballots at random, and teams compare each paper ballot with the system's record of it.

The random seed comes from rolling 20 ten-sided dice at a public meeting, so no official chooses the sample. Colorado began with a risk limit of 9% and has lowered it to 3%, the limit for the 2026 general election. If the sample shows differences, counties may have to audit more ballots.

How does India check its voting machines against paper slips?

Indian elections use electronic voting machines (EVMs) joined to VVPAT printers. Each vote prints a slip with the candidate's name and symbol, lit behind glass for 7 seconds before it drops into a sealed box. In 2013, the rules were amended to bring in VVPATs, and the Supreme Court called a paper trail indispensable.

After the electronic count, slips from five randomly selected polling stations in each assembly segment are counted by hand and compared with the machines. The Court raised this from one in April 2019. If slips and machine differ, the rules say the result follows the paper.

Petitioners then asked for every slip to be counted, or for paper ballots, saying EVMs could be manipulated. On 26 April 2024, the Court refused. It recorded that more than 4 crore (40 million) slips had been tallied with one mismatch, traced to mock-poll votes an officer failed to delete.

The Court added two safeguards. The units that load symbols into VVPATs must be sealed and kept for at least 45 days. The second- or third-placed candidate may ask engineers, at the candidate's cost, to check the memory of 5% of machines in each assembly segment.

Why did Germany's top court reject the voting computers used in 2005?

At the 2005 Bundestag election, about two million voters in five German states used Nedap voting computers. They stored votes electronically, with no paper record. On 3 March 2009, the Federal Constitutional Court ruled their use unconstitutional.

The court drew a principle of the public nature of elections from Articles 38 and 20 of the Basic Law. Citizens must be able to check every essential step of voting and of finding the result, reliably and without specialist knowledge. A printed summary of the machine's total was not enough.

The court declared the ordinance approving the machines unconstitutional. It did not order a new election, as there was no sign the machines had failed or been manipulated. Machines could still be used, it said, if they also recorded votes another way, such as on paper.

What happened when counts were disputed in Florida and Western Australia?

After the 2000 presidential election in the United States, Florida reported George W. Bush ahead of Al Gore by 1,784 votes. That was under half a percent, so state law required an automatic machine recount, which narrowed the lead.

On punch-card ballots, a vote could fail to register if a piece of card, a chad, was left hanging. The Florida Supreme Court ordered hand counts of ballots on which machines had found no vote for president. On 12 December 2000, in Bush v. Gore, the US Supreme Court held that this recount lacked specific standards for judging voters' intent, and it ended the recount.

Western Australia's 2013 Senate election failed on custody. In a recount from 17 October 2013, the Australian Electoral Commission (AEC) found 1,370 ballot papers missing. Given the close margins, the AEC itself asked the Court of Disputed Returns to void the result.

An inquiry by Mick Keelty found significant failures in handling, moving and storing ballot papers, but no evidence of deliberate destruction. Justice Hayne voided the result on 20 February 2014, and a new election was held on 5 April 2014.

How does this work with real numbers?

Both examples use illustrative numbers, not real results.

How does a polling station's ballot paper account balance?

A station receives 1,200 ballot papers. Its presiding officer records 846 issued, 4 spoilt and 350 unused. Since 846 + 4 + 350 = 1,200, every paper is accounted for.

At verification, the box holds 845 papers, one fewer than issued. Staff reach 845 twice in a row, so 845 is verified and the gap of one recorded.

Table: The illustrative second count

The piles add up to the verified 845. A's lead of 23 votes dwarfs the gap of one, which cannot change the result.

How many ballots does a risk-limiting audit need?

Take a contest with 200,000 ballot cards: 105,000 for the reported winner and 85,000 for the runner-up. The margin is 20,000 votes. The diluted margin divides it by all ballot cards: 20,000 ÷ 200,000 = 10%.

Philip Stark's formula for a comparison audit gives the starting sample. If no errors are found, it reduces to: 2 × 1.03905 × ln(1 ÷ risk limit) ÷ diluted margin. Here 1.03905 is the default setting of a tuning factor in his tool, and ln is the natural logarithm.

At a 5% risk limit, ln(20) ≈ 2.996, so the top line is about 6.23.

Table: Starting sample at a 5% risk limit, with no errors found

For a given diluted margin, the number of ballots cast does not change the sample. If a winner with a wide margin had really lost, many ballots would have been misread, and a small random sample would almost surely catch some. Errors found make the audit grow.

Where can the student go deeper in World 101?

This page follows ballots from the close of the poll to a checked result. The World 101 subject Elections and Voting covers the wider field, from why societies choose leaders by vote to how electoral systems turn votes into seats and who may vote.

Three related subjects go further. Statistics and Data explains random sampling and why a small, well-chosen sample can describe a large population, the idea behind every audit. Cybersecurity covers how digital systems are protected and tested, the worry behind public checks on voting machines. Disinformation and Elections looks at false claims about how votes were counted, and why checkable records matter when a result is disputed.

Sources

• City of Edinburgh Council, count guidance for the UK Parliamentary Election 2024 and the Local Government Election 2022 (Ballot Paper Account), read 7 November 2026.
• The 2026 Florida Statutes, sections 102.141 and 102.166.
• Colorado Secretary of State, Risk-Limiting Audit FAQs (law of 2009; first statewide audit, 2017; risk limit 9% to 3%) and Audit Center (3% for 2026), read 7 November 2026.
• J. L. Hall, P. B. Stark and others, "Implementing Risk-Limiting Post-Election Audits in California", EVT/WOTE, 2009.
• P. B. Stark, "Tools for Comparison Risk-Limiting Election Audits", last modified 9 June 2020 (citing his "Super-Simple" audits paper, EVT/WOTE, 2010).
• Supreme Court of India, Association for Democratic Reforms v. Election Commission of India, 2024 INSC 341, 26 April 2024, recording Subramanian Swamy (2013) and N. Chandrababu Naidu (2019); Supreme Court Observer on the order of 8 April 2019.
• Federal Constitutional Court of Germany, Judgment of 3 March 2009, 2 BvC 3/07 and 2 BvC 4/07 (2005 Bundestag election), and Press Release No. 19/2009.
• Bush v. Gore, 531 U.S. 98, per curiam, 12 December 2000.
• Australian Electoral Commission, WA Senate recount advisory, October 2013; media releases of 15 November 2013, 6 December 2013 and 20 February 2014; 2013 WA Senate results (new election, 5 April 2014).

Common errors and misconceptions

• Misconception: A recount and an audit are the same thing. Correct: A recount counts the ballots again; a risk-limiting audit checks a random sample and grows only when the evidence is weak.
• Misconception: A larger electorate needs a larger audit sample. Correct: For a given diluted margin and risk limit, the starting sample is the same however many ballots were cast.
• Misconception: Electronic voting can never be checked by the public. Correct: Machines that keep a voter verifiable paper record can be checked against it; Germany's court objected to machines without such a check.
• Misconception: In Bush v. Gore, the US Supreme Court counted the Florida ballots. Correct: It counted nothing; it held that the ordered recount lacked specific standards for judging intent, and ended it.
• Misconception: Any mismatch in a count proves fraud. Correct: Counts record and investigate every difference. India's one VVPAT mismatch was traced to undeleted mock-poll votes.

Key takeaways

• Counting starts with reconciliation: the ballots in each box must match the number the presiding officer recorded as issued.
• Machines count fast, but a paper record made in front of the voter lets people check them later.
• Recount rules differ: UK candidates may ask for one, while Florida orders one when a margin is half a percent or less.
• A risk-limiting audit samples paper ballots at random until the evidence meets a preset risk limit, or it becomes a full hand count.
• India counts VVPAT slips from five random polling stations per assembly segment; in April 2024 its Supreme Court declined to order a count of every slip.
• Germany's 2009 ruling requires that citizens can check each essential step; 1,370 lost ballot papers made Western Australia vote again in 2014.

Test yourself

What does verification check at a UK count?

That the ballot papers in each box match the number the presiding officer recorded as issued, before votes are sorted.

Why does a risk-limiting audit need paper ballots?

It compares a random sample of a trustworthy paper record with the machine count; without paper, nothing independent remains to check.

Why does the illustrative 10% diluted margin need only 63 ballots?

At a 5% risk limit, 6.23 ÷ 0.10 ≈ 62.3, rounded up to 63. A wrong result with so wide a margin would leave many misread ballots to find.

What two safeguards did India's Supreme Court add on 26 April 2024?

Symbol loading units are sealed and kept for at least 45 days, and the second- or third-placed candidate may have 5% of machines per segment checked.

On what principle did Germany's Federal Constitutional Court rule in 2009?

The public nature of elections: citizens must be able to check every essential step of voting and counting without specialist knowledge.

Why was the 2013 Western Australian Senate election held again?

A recount found 1,370 ballot papers missing. With margins so close, the court voided the result, and a new election followed in April 2014.