Tellers are the Members who count the votes in the House of Commons and the House of Lords during a division (vote). There are four tellers, two from each side of the House, who are usually also whips. Once the division (voting) is over the tellers announce the results to the House.
In the House of Lords after the clerks have counted the votes, the teller from the winning side informs the person on the Woolsack/Chairman of the Committee who then announces the results to the House.
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Related glossary term: Divisions
Related glossary term: Whips