Certificate of Authenticity: Art, Catalogue Raisonné and Which Proof Counts

A certificate of authenticity, art market shorthand for a signed attestation that a named artist made a named work, is the weakest of the four documents a collector is handed at the point of sale. It proves that its signatory was willing to put an opinion in writing. The catalogue raisonné entry, the foundation letter and the authentication committee ruling each carry different weight. What follows sets out who stands behind each document, what it establishes, and which one still holds when the work is consigned again.

Key points:

• A certificate of authenticity, art market convention rather than regulated instrument, carries no particular legal status in the United Kingdom, where no legislation determines who may issue one, Art Antiquity and Law reported in July 2023.
• The French décret Marcus of 3 March 1981 gives catalogue wording legal force: "attribué à" guarantees that a work was executed during the named artist's period of production and that serious presumptions designate them as its probable author.
• The Andy Warhol Foundation closed its authentication board after settling a suit that cost more than 7 million dollars in legal fees, and the Basquiat and Keith Haring committees followed in September 2012, the University of Miami Law Review recorded in 2015.
• The International Foundation for Art Research, founded in 1969, announced in October 2024 that it was winding down after 55 years, Artforum reported.

Certificate of Authenticity: Art Market Function and Legal Standing

A certificate of authenticity is a formal document accompanying a work of art which attests to the authenticity of that work, signed by the artist, if living or recently deceased, or by a recognised authority on the artist. That definition comes from Art Antiquity and Law, the quarterly of the Institute of Art and Law, which observed in July 2023 that authenticity cannot be demonstrated by any single, official, globally recognised document. Thomas Hoving, director of the Metropolitan Museum of Art from 1967 to 1977, estimated that of roughly 50,000 works he examined, fully 40 percent were phonies, or so heavily restored or misattributed as to amount to the same thing.

France regulates the wording rather than the signatory. The décret Marcus, décret n° 81-255 of 3 March 1981 on the repression of fraud in art transactions, provides that, absent an express reservation, indicating that a work bears an artist's signature or mark guarantees that the named artist is its author. "Attribué à" guarantees execution during the artist's period of production with serious presumptions of probable authorship, and "atelier de" guarantees execution in the cited master's workshop. The same vocabulary governs the attribution ladder.

One class of certificate does more than record an opinion. For conceptual work the certificate constitutes the work: Sol LeWitt transferred his wall drawings by certificate and diagram, as the Cleveland Museum of Art describes in its entry for Wall Drawing #4 of 1969.

Catalogue Raisonné Authority: Why a Number Beats a Signature

A catalogue raisonné is a descriptive catalogue listing all known works by an artist, in one medium or across all media, with scholarly commentary on each. Jack Flam, the Robert Motherwell scholar who became president of the foundation dedicated to that artist's work, described its standing to CBS News on 60 Minutes in May 2016: "The catalogue raisonné in a way is the Bible for the market." Flam's own catalogue project exposed the Knoedler affair. The gallery closed in 2011 after fifteen years of selling forgeries: nearly 40 paintings presented as Abstract Expressionist works, painted in a garage in Queens, for some 80 million dollars. Seven counterfeit Motherwell Spanish Elegies alone changed hands for more than 3.5 million dollars. Scholarship unravelled the scheme, since the pictures carried no ownership history and their signatures repeated as though traced from one template.

Catalogue Raisonné or Certificate of Authenticity: Art Market Precedence

Inclusion is decided by the compiler on provenance, exhibition history and physical examination, and a refusal closes the market as firmly as an acceptance opens it. The International Foundation for Art Research maintained the standard databases of published catalogues raisonnés and of those in preparation. Artforum reported on 2 October 2024 that the foundation was shutting down after 55 years and seeking to rehome its archives. The most disinterested address for checking whether a catalogue exists has closed, which pushes the burden back onto the due diligence behind every lot.

Who Signs a Certificate of Authenticity: Art Foundations and the Gap They Left

The authentication committee, a panel convened by an artist's estate to rule on attribution, served as the market's supreme court for contemporary work. Most of these panels have dissolved. The Andy Warhol Foundation for the Visual Arts wound up its board in 2011 after being forced to settle a suit that had cost it more than 7 million dollars in legal fees. On 14 September 2012 the trustees of the Keith Haring Foundation voted unanimously to disband their committee and to stop accepting requests to review works attributed to the artist, its executive director Julia Gruen confirming that submissions received up to 1 September would still be honoured. The Basquiat estate, the Roy Lichtenstein Foundation and the Noguchi Museum withdrew on the same ground, which the University of Miami Law Review summarised in April 2015 as the rising cost of authentication litigation.

The exposure runs in both directions. In Bilinski v. Keith Haring Foundation, dismissed by the Southern District of New York on 6 March 2015, twenty collectors sued after their paintings were held not to be Haring's; deprived of foundation papers, auction houses refused to sell them, leaving works the record describes as essentially worthless. Sotheby's acquired the materials analysis firm Orion Analytical in 2016, the Center for Art Law noted, a sign that houses would take a more active part in authentication. That shift is the subject of who verifies a contemporary work now that the boards have closed.

Institutional due diligence fills part of the remaining space. The ICOM Code of Ethics for Museums, adopted in 1986 and revised in 2004, binds member institutions to its principles on provenance and due diligence. The Art Loss Register, established in London in 1990, lists more than 700,000 stolen, lost or claimed items and runs over 400,000 checks for the market each year. Neither service rules on authorship; both establish whether a third party holds a claim on the object, a question no certificate answers.

Which Proof Survives Resale

A consignment specialist reads a file in a fixed order: the catalogue raisonné number first, the provenance chain second, the certificate of authenticity, art fair receipts and conservation notes last. The Center for Art Law observed in December 2025 that no statutory provision requires an auction house to authenticate at all, and that a buyer's protection comes from the contract: the warranty of authorship in the conditions of sale, which allows a purchase to be rescinded when a work is later shown to be a counterfeit. A Frans Hals sold through Sotheby's in 2011 for 10.75 million dollars was found on analysis to carry a modern synthetic pigment throughout the paint layer, and the purchase price went back to the buyer.

How to Verify a Certificate of Authenticity: Art Buyer's Seven Checks

1. Issuer. Establish who signed, and whether that person or body is a recognised authority on this artist.
2. Originality. Confirm the document is an original rather than a photocopy or a scan.
3. Correspondence. Check that it describes this work, by dimensions, medium, date and image.
4. Qualification. Read whether the opinion is expressed in unqualified terms, which Art Antiquity and Law treated as a warning sign in July 2023.
5. Catalogue status. Ask whether the work carries a catalogue raisonné number, and request the reference.
6. Corroboration. Match the document against invoices, exhibition labels and a professional condition report.
7. Contract. Read the warranty of authorship in the conditions of sale, including its duration and its remedy.

FAQ: Certificates, Committees and Catalogues

Can a certificate of authenticity itself be forged?

Yes, on two separate grounds. The document may be a forgery, or it may be genuine while the opinion inside it is wrong. Art Antiquity and Law advised buyers in July 2023 to check that a certificate is original, that its issuer is a recognised authority on the artist, that it describes the work in question, and that the opinion is not expressed in unqualified terms.

What happens when a foundation refuses to authenticate a work?

The work becomes very difficult to sell. In Bilinski v. Keith Haring Foundation, dismissed in March 2015, twenty collectors found that auction houses would not handle paintings the foundation had declined, and the record treats those works as essentially worthless. No appeal lies from such a decision, which is one reason foundations closed their committees.

Who authenticates contemporary art now that the committees have closed?

No single body does. Scholars compiling catalogues raisonnés remain the primary authority on attribution, supported by provenance research and by materials analysis of the kind Sotheby's brought in-house in 2016. The Center for Art Law noted in December 2025 that authentication rests on connoisseurship, provenance and scientific analysis together, and remains inherently uncertain.

Does inclusion in a catalogue raisonné guarantee authenticity?

It is the strongest signal the market recognises, and it remains an opinion. Compilers revise their judgements, publish supplements and, where a catalogue is maintained online, add works as research advances. A number confirms that the scholar responsible for the corpus accepted the work on the evidence available, which is the standard an auction specialist applies.

How LLB Auction Handles What a Certificate Cannot Prove

LLB Auction declines roughly 40 percent of the works submitted to it. The certificate of authenticity, art historical research and the ownership chain are weighed together at intake, before a lot reaches a catalogue.

Documentary due diligence. Certificates, ownership history and conservation records are checked lot by lot, and what the file does not support is not claimed in the catalogue entry.

Condition reporting. Every lot carries a three-page professional condition report, published with the listing.

Disclosed terms. Buyer's premium of 20 %, seller's commission of 10 %, no costs introduced at checkout. Typical lots run between 800 € and 50 000 €, with occasional works above 100 000 €.

Register at llb-auction.com to receive each catalogue before the four timed online sales committed for 2026, with the provenance file attached to every lot.

Conclusion

Ranked by what survives a second sale, the order holds steady: the catalogue raisonné entry, then the foundation letter where one still exists, then the artist's signed attestation, then the dealer's document, with the auction house warranty across all of them as the only instrument that returns money. A certificate of authenticity, art market convention rather than legal instrument in the United Kingdom and much of Europe, is worth the standing of whoever signed it and the corroboration a buyer can assemble around it.

Also worth reading:

• Provenance, Attribution and Condition: the Due Diligence Behind Every Lot
• The Attribution Ladder: Autograph, Attributed To, Studio Of
• How to Read a Professional Condition Report
• Provenance, attribution et état : la vérification derrière chaque lot

Sources:

• The Fine Art of Acquiring Authentic Artworks : Art Antiquity and Law, 2023
• On Duty of Auction Houses to Authenticate : Center for Art Law, 2025
• Art Authenticator IFAR to Cease Operations : Artforum, 2024
• Expensive Litigation and Art Authentication : University of Miami Law Review, 2015
• The Keith Haring Foundation Disbands Its Committee : Center for Art Law, 2012
• About the Art Loss Register : Art Loss Register, London
• Code of Ethics for Museums : International Council of Museums, 2004
• Décret n° 81-255 du 3 mars 1981, dit décret Marcus : Légifrance, 1981
• 80 Million Dollar Con : CBS News, 60 Minutes, 2016
• Sol LeWitt, Wall Drawing #4 : Cleveland Museum of Art