If you are creating a code using a prefix that is set up with a custom format, you will be required to enter an Ad-ID Code. Characters can be numbers and/or letters. The prefix SHOULD NOT be included as part of the code entered.
Ad-ID customer service is not responsible for providing instructions on what characters to enter. If the prefix administrator set up instructions, they will be displayed under the Prefix drop down on the code creation screen. This may include a contact to reach out to with questions.
Custom 4: You must enter 4 characters and they CANNOT be changed once the code is created. If the 4 characters have already been used under this prefix, the overflow zeroes will use alpha-numeric characters to make the code unique.
Custom 7: You must enter 7 characters and they CAN be changed after the code is created, if needed. If the 7 characters have already been used under this prefix, an error will be provided and you will need to enter a new code.
See What is an example of an Ad-ID code? for more details on the Ad-ID code structure.