If you received a Halo Collar secondhand from another user, they must remove the collar from their account before you can add it to yours. 

For instructions on how to remove a collar from an account, please see this article. 

Additional Notes

• A collar that has been transferred to another user is no longer returnable, even if it is still within the 'return period.' Additionally, the Halo Collar Warranty is not transferable and applies only to the original consumer purchaser.
• For security reasons, our Customer Service team cannot delete a collar from an account without the explicit written permission of the original owner.  (If this is not possible, a receipt showing a purchase from the original owner should suffice)

If you have any further questions and would like to speak to our live support team, please feel free to reach out using the following article: How to Contact Customer Support, and we'll be happy to help!