Adding primary or authorized user tradelines to your credit report can significantly boost your credit score. Here’s how:

1. Improved Credit History: By adding a tradeline with a long, positive credit history, you can enhance the average age of your accounts, which is a key factor in credit scoring models.

2. Higher Credit Limit: Increasing your available credit can lower your credit utilization ratio, another crucial factor in your credit score. A lower utilization rate indicates responsible credit management.

3. Positive Payment Record: A tradeline with a consistent record of on-time payments can demonstrate reliability and boost your credit score.

4. Diverse Credit Mix: Adding a new type of credit account can improve your credit mix, which can positively impact your score.

By strategically adding primary or authorized user tradelines, you can effectively build or improve your credit score, opening doors to better interest rates and lending opportunities.