Definition
A Certificate of Authenticity (COA) is any document attached to an item asserting its authenticity. COAs can be issued by recognized third-party authenticators (PSA/DNA, JSA, BAS), by dealers, by signing-event organizers, or by celebrities' management. Market trust varies enormously by issuer.
Why it matters
A COA is only as credible as its issuer. A trusted third-party COA can multiply value 3–10x; a COA from an unknown issuer often has no effect on price.
Example
A signed jersey arrives with a PSA/DNA COA that includes a hologram and an online lookup. The buyer verifies the certificate by entering the hologram number on the PSA database.
Related terms
- AuthenticationA third party verifying that an item is what the seller claims it is.
- Letter of AuthenticityA long-form authentication document, typically from a recognized third-party authenticator.
- Third-Party AuthenticatorAn independent company that authenticates items without being the buyer or seller.