The enrollment forms with the price structure is here. 2021 Enrollment Form
In addition to the enrollment fee there is a per head data fee for any animal that you turn a post-birth measurement in on if it has not been marked as a cull or commercial animal. If you read the enrollment form it refers to section 4.14 in the Quality Assurance Manual. In there it tells you that you need to put a CU or a CO in the tag number to indicate the culls and commercial animals. The CO & CU belong in the 11 & 12 digit location. You should not mark more than 25% of your lamb crop this way. It is also where a lot of us US breeders are putting letters to indicate our flocks. CO & CU should not be used for anything besides this cull & commercial reason. This does mean that you would have to do a retag with the CO or CU at the time that you enter a post-birth measurement if you already have sent partial data (i.e. birth info) in on them and do not want to be billed for that animal.
Association Memberships are available for supporters of NSIP that do not submit data (i.e., breed associations, meat companies, industry affiliates, individuals, and flocks generating EBVs and EPDs via other programs). Associate Members do not have voting privileges, but will be included on our website and in correspondence sent to all NSIP members.