Our team at Sports Investors Authentication exists to provide the highest overall quality sports memorabilia authentication services for game used items. Supporting this vision is our pillars of passion for all things sports, our collective expertise, genuine care for our clients and partners, and pursuit of bringing integrity to the industry by leading the way. As an accompaniment to our services, we offer the following documentation for memorabilia submissions:

  • Auction Letters: For our clients who operate auction houses, we provide comprehensive inspections of various lots to determine authenticity and subsequently levels of game use. Items which receive a favorable Auction Letter are permitted to receive further authentication services from Sports Investors.
  • Letters of Authenticity: Extensive letter detailing full submission evaluation. Delineates item specifications, portrays general item photos, designation of game use (if applicable), identification of performance and milestones (if any), brief explanation of provenance (case by case variation), and contains a final opinion with Managing Member and Lead Authenticator signatures.

  • Letters of Provenance: Details more exhaustive record of pertinent information regarding memorabilia origins and history of ownership. Strongly encouraged for items of antiquity, immense value, and to increase confidence of items of the like whose authenticity stands questionable.

  • Letters of Opinion: These letters exist for items of inconsistent style characteristics and/or suspicion of alteration/reproduction. Provenance is questionable or non existent. No examples of definitive photo matches are found.


Read more about our authentication process here.