What is a certificate of authenticity worth?
A certificate is only as trustworthy as the person who issued it. It is useful as a record of the meteorite's name, type, weight and source, but it is not an independent scientific verification, and anyone can print one.
Many meteorites are sold with a certificate of authenticity, often a neat card or printed sheet. It can be genuinely helpful, but it is easy to overestimate what it proves.
A certificate is a statement by the seller, or sometimes by a previous owner, that the specimen is what they say it is. It does not come from an official body, and there is no universal standard for issuing one. A reputable dealer's certificate carries weight because of that dealer's knowledge and track record, and because they are likely to stand behind it if a problem arises. A certificate from an unknown seller may mean very little, and fake certificates can be produced as easily as fake specimens.
What makes a certificate useful is the information on it. A good one gives the meteorite's official name as approved by the Meteoritical Society, its classification (for example H5 or eucrite), the mass of the specimen, a photograph or specimen number matching the piece, and the seller's full contact details. With those, you can check that the name exists in the society's public catalogue and that the classification matches. It also forms part of the specimen's provenance, the record of where it came from and who has owned it, which can matter later if you sell or donate the meteorite.
So keep certificates safely with your specimens, but treat them as a label rather than a guarantee. The real assurance comes from a genuine, classified meteorite bought from a trustworthy source. If you ever have serious doubts about a specimen, a museum or university geology department can examine it, and that independent opinion is worth far more than any printed card.