Ad-ID recommends registering a prefix for each advertiser/client. There is no cost to register a prefix. If an agency would like to register a prefix to use for multiple clients, they can contact customer service to request an unlocked prefix.
Unlocked prefixes can be licensed to agents (ad agencies, distribution companies, production companies, etc.) and can be used to create codes for any advertiser who does not have a registered prefix. If the advertiser already has a registered prefix, you will be required to use that prefix and cannot use an agency (unlocked) prefix.
When creating codes with an unlocked prefix, you must find the appropriate parent company to assign the code to. The parent company CANNOT be the agency, it must be the advertiser/client the ad is promoting. If you cannot find the appropriate parent company, please contact customer service.