The Business Challenge at this year's is already the most successful ever - 11 weeks before the event starts on October 19.
Organisers say they have now topped the 407 runners who signed up for the Business Challenge in 2013, when a total of 20,000 people took on the 13.1-mile course.
David Hart, communications director for the Bupa Great Birmingham Run, said companies had responded like never before.
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He said: "The response has been incredible - we've noticed not only new names but many companies entering bigger teams than they did in 2013.
"It's the perfect team bonding event, as well as raising vital funds for businesses' nominated charities."
Companies which have already registered include Birmingham Children's Hospital, Fox's Biscuits, Delcam, HSBC, Geese Theatre Company, JW Hinks and Tata Motors.
Last year's winners included Rugby Club, Citadel Chambers and Deloitte. The Bupa Great Birmingham Run is the second biggest half marathon in the 海角视频.
Teams must be between four and eight people but a business can enter as many teams as it wants in the male, female and mixed-sex categories.
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Mixed teams must have a minimum of two men and two women and team members must be 16 years of age or over on race day.
Placings are based on the accumulated first four finishing times in each team.
Every team that enters 12 or more employees will receive their own personalised company engraved plaque.
* To register go to:
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