What is a clock number?

Ad clock numbers

Find out what clock numbers mean and how they’re allocated

A clock number is a unique alphanumeric identification number. It identifies an advertisement and its creators or source (usually an advertising agency).

The number is used from when we clear and ad, right through to when the ad is transmitted — and subsequent reporting.

What is a clock number and how do I get one?

A clock number consists of several groups of letters or numbers. Each group provides a piece of information.

This is the format of a clock number:
AAA/BBBB123/456

  • The 1st three letters of the clock number must be your Agency Code. This will be created and sent to you by Clearcast after registering with us
  • The middle section of the clock number is made up of four letters followed by three numbers. This section is created by you. The four letters must be something relevant to either the agency, client or product. For the three numbers use ‘001’ for your first ad submitted to us, ‘002’ for your next one etc. If preferred you can use your own internal numbering, please ensure it’s three digits
  • The last 3 digits should be the duration of the ad so for example a 30 sec ad will be ‘030’

This clock number must be clearly displayed onscreen whilst the countdown clock counts down.

Who creates clock numbers?

Agencies or advertisers are responsible for making up the clock number, but we allocate the agency code in the clock number.

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