Central Senate Scrutiny

Updated: 30 April 2019

The scrutiny of all returned Senate ballot papers is conducted at the Central Senate Scrutiny (CSS) in each state or territory. The Australian Electoral Officer (AEO) for the state or territory is responsible for the scrutiny of ballot papers at the CSS.


Prior to the 2016 election, fewer than three per cent of Senate ballot papers contained below the line (BTL) votes, requiring preferences to be manually entered. As a result of the legislative changes to voting that took effect before the 2016 election, data entry was needed for all Senate ballot papers – more than 14 million – and it is anticipated this number will rise progressively at future elections due to the natural increase in enrolment due to population growth.

At the CSS, the AEC uses a semi-automated Senate count solution that scans Senate ballot papers and uses optical character recognition technology to capture preferences. Once captured, these preferences are then verified by a human operator. The images of potentially informal ballot papers and those with unusual markings, are visually checked by a different human operator and assessed as formal or informal by AEC staff.

The solution was developed by the AEC in partnership with Fuji Xerox for the 2016 federal election and significantly reduces the human effort, time and cost of capturing voter preferences. 

Senate ballot paper process

  • After 6pm on election day, all polling places complete a first preference count of Senate ballot papers at the polling place.
  • Indicative first preference results are published to the AEC Tally Room and AEC federal election app.
  • Ballot papers are sent to the divisional out-posted centres where they are reconciled, counted again, batched and sent to the CSS in each state and territory.
  • At the Central Senate Security (CSS), all ballot papers are scanned for entry into the semi‑automated scrutiny process.
  • The semi-automated scrutiny process captures preferences using a combination of optical character recognition software and manual verification by a human operator.
  • Scrutineers may view the verification process and, if they wish, raise challenges for adjudication by the Australian Electoral Officer (AEO). In 2019, larger monitors and more space around exception queue workstations will be provided in order to give scrutineers greater visibility of ballot papers in the exception queues.
  • The images of potentially informal ballot papers, and those with unusual markings, are visually checked by a human operator and potentially assessed informal by AEC staff.
  • The preferences captured during the semi‑automated scrutiny process are stored in electronic tamper‑proof files.
  • These files are transferred to the AEC progressively, which loads the preferences and reports the progress results.
  • Once all ballot paper data is received at the AEC it is transferred to the count system where the distribution of preferences is run and final results determined
  • The final results are published to the AEC Tally Room.
  • Lastly, ballot papers are sent to secure long-term storage.

How long does the Senate count take?

The Senate count is more complex than the count for the House of Representatives and takes longer to complete. This is because it involves the election of multiple members for each State and Territory, which means that candidates must receive a quota or proportion of votes to be elected rather than a simple majority.

In order to determine this quota all Senate ballot papers need to be assessed for formality, so while counting of first preferences begins on election night, the full count cannot be completed until up to five weeks after the election.

Role of Scrutineers at Central Senate Scrutiny

Scrutineers are able to monitor the processing of Senate ballot papers at CSS centres in each state and territory capital city.

At the 2019 federal election, to accommodate scrutineers and provide greater visibility of ballot papers in exception queues, larger monitors and more space around workstations will be provided.  Candidates are entitled to appoint one scrutineer for each AEC officer involved in the central Senate scrutiny. Fuji Xerox staff are not AEC officers and therefore do not count towards determining the number of scrutineers allowed.

CSS site operations: scrutineer access and requirements

The CSS sites operate after election day and are located at Fuji Xerox premises. While the ballot paper secure work zone is dedicated to scrutiny, other areas of the site unrelated to the scrutiny of the count will be operating. Fuji Xerox requires all visitors to their facilities to adhere to safety requirements.

  • Each site has a scrutineer coordinator.
  • Each site has a designated location for scrutineer induction.
  • Scrutineers are required to participate in two inductions: one from the AEC regarding the scrutiny and one from Fuji Xerox regarding safety at the site.
  • Scrutineers will be issued with identification passes which they are required to wear when on the CSS site.
  • AEC staff are required to wear colour-coded bibs.
  • Scrutineers are required to register, sign in, and wear high vis vests.
  • At the CSS site scrutineers will be accompanied at all times.
  • At some CSS sites hearing protection may be required.
  • Areas are zoned for security and safety purposes and clearly signed.
  • Mobile phones are not permitted in ballot paper secure work zones.
  • Eating and drinking is not permitted in the ballot paper secure work zones.
  • Fuji Xerox will have security guards on site.

CSS site information

The below guides provide scrutineers planning to attend CSS centres information about location, processes to follow, and planned hours of operation noting that these may change subject to processing requirements. Contact the AEC office in your state or territory to confirm the hours of operation. All scrutineers attending a CSS site will also be given a scrutineer induction and a site induction.

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