COA vs LOA: What Is the Difference?
Certificates of Authenticity, Letters of Authenticity, and authentication slips — what each one means and which the market trusts.
Short answer
The terms “COA” and “LOA” are used inconsistently. Here's how the secondary market actually treats each one.
COA: a category, not a guarantee
“Certificate of Authenticity” describes any document attached to an item asserting authenticity. The issuer can be:
- A recognized third-party authenticator (PSA/DNA, JSA, BAS, etc.)
- A dealer or store
- A signing-event organizer
- The celebrity's management
- A small one-person operation
Quality varies enormously. A PSA/DNA COA with a hologram and online lookup is qualitatively different from a printed-on-cardstock COA from a dealer no one has heard of. Both are technically COAs.
LOA: typically long-form, third-party
“Letter of Authenticity” usually refers to a multi-paragraph document from a recognized third-party authenticator detailing what was examined, what signature was authenticated, and the verifier's opinion. LOAs are typically issued for higher-value items where the authenticator wants to attach a narrative — for example, JSA full LOAs for cut signatures or signed photographs.
What the market trusts
| Document | Market trust |
|---|---|
| PSA/DNA, JSA, BAS, SGC, CGC LOAs / hologram authentications | Strong |
| Steiner, TriStar, Topps Now-style authenticated signings | Moderate — venue-backed |
| Signed and dated dealer COAs from established dealers | Moderate |
| In-store signing-event certificates | Variable |
| Hand-stamped or printed COAs from unknown issuers | Weak |
Don't pay for a COA without lookup
The simplest test: can a buyer look up the COA in the issuer's database? PSA/DNA, JSA, and BAS all maintain online lookups by COA number. If the COA can't be verified independently, it's an asserted opinion, not a verifiable one.
Frequently asked questions
Related guides
Keep reading
Why Some COAs Are More Trusted Than Others
The four characteristics that make a Certificate of Authenticity credible — issuer reputation, lookup-ability, methodology disclosure, and aftermarket recognition.
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