The mighty clock number

18th October 2018

This article was originally published in our Autumn 2017 Newsletter, but it’s always good to be reminded about The Mighty Clock Number.


If you’re reading this you almost certainly know about the clock number, the 15 character unique identifier for TV commercials. The UK is advanced compared to other markets in having had a standard clock number system for many years. You may not have given it much thought, but here’s why the clock number is so important:


  • By providing a unique identifier, the clock number ensures that the right ad is broadcast. That’s why Clearcast manages the first three characters to ensure every agency has a unique identifier and CopyCentral double checks to see if a number has been used before


  • It’s also used by agencies to keep track of the visual artists, composers, musicians and other rights holders associated with a commercial. That helps ensure artists are paid


  • It allows Clearcast’s Attribution service to provide additional metadata, like Nielsen category, Advertiser and Holding Company. This in turn allows post campaign and share of voice analysis on systems like those provided by Media Ocean, Kantar and Techedge


  • Broadcasters, digital publishers and ad serving companies use the clock number to check if an ad has been cleared by Clearcast. Historically this was a manual process but now more often is automated through the use of the CopyCentral API, a constantly updated feed of the status of our clearances


  • Broadcasters also use the clock number to identify where artists need to be kept away from children’s programmes in which they appear (a BCAP code requirement) and opportunities for scheduling ads featuring artists in other programmes where there is a synergy



It’s also one area where linear TV advertising and VOD is ahead of programmatic platforms; there is currently no similar standard for digital assets, which makes digital campaigns on these platforms much harder to manage and track.


So next time you type in a humble clock number, think about the great British success story it represents.