This is an educational profile built from public sources. It isn't a rating, an endorsement, or an opinion on any item or seller. How we source facts. Last researched Oct 12, 2026.
Who runs it, and where
Major League Baseball runs this program. Authenticators witness a signing or game use and then apply a tamper-evident hologram. [1]
As of Oct 12, 2026, MLB Authentication does not appear on eBay's published list of people and organizations whose COAs/LOAs are not allowed. That list is not an endorsement, and eBay says COAs are only as valuable as the reputation of the issuer. [4]
