There are three main expertizing services in the US: the Philatelic Foundation (PF), Professional Stamp Experts (PSE), and the American Philatelic Expertizing Service (APEX, run by the American Philatelic Society). A fourth, Philatelic Stamp Authentication and Grading (PSAG) was founded in 2009. For completion, I should include the Confederate Stamp Alliance which only certifies Confederate items.
All of the committees are competent. Various experts serve on these committees and render opinions on the genuineness of submitted items. Some experts issue opinions for more than one committee. An expert on a committee is never allowed to render an opinion on an item they submit. That is an obvious conflict of interest. Committees are composed of highly knowledgeable members with many years of experience. Expertizers serve as an apprentice for a period of time before becoming full-fledged committee members.
Why obtain a certificate in the first place?
The main reason is to obtain an independent, unbiased opinion as to an itemís genuineness from a source that has no financial stake in the item. When you decide to sell the stamp to someone else, you can say, ďIt has a certificateĒ. The buyer is more confident that they are buying a genuine item.
Certificates come in three forms: clean (or clear), bad, or no opinion.
A clean certificate means the item is genuine. A clean certificate has nothing to do with condition. You could have a used copy of Scott #39 which is very rare. If the stamp is heavily damaged and basically a space filler, it can still have a clean certificate as long as itís genuine.
Certificates note hinging (previously hinged or never hinged) for mint stamps. Faults or alterations are noted such as: reperforation, regumming, altered cancels, thins, tears, and so forth. Clean signifies the item is a genuine copy of a certain Scott number. Read the certificate closely to note any additional comments the committee made.
Bad certificates are for items that are fakes or forgeries. For example, adding perforations to an imperforate stamp to make it appear to be a rare coil issue. Or adding perforations and gum to a proof to make it appear to be an actual stamp. A bad certificate is for an item that is not what it appears to be.
There is still a use for items with bad certificates. Expertization committees use them as reference material. People collect them for reference purposes. Fakes and forgeries still serve a useful purpose as a reference point for comparison to other items.
On rare occasions, a committee may decline to offer a certificate on a particular item. There may be contradictory or insufficient evidence. That doesnít say that an item is definitely a fake. It just means that the committee couldnít come to an agreement on that extraordinary item.
A certificate is not a 100% guarantee for life. There have been cases where items with a bad certificate are given a clean certificate. Conversely, items with clean certificates come back with a bad certificate. Yes, sometimes the committee makes a mistake on an item. Humans are involved. Mistakes are possible. Most of the time though, a change in a certificate is due to new evidence coming forward or improved techniques that spot things that werenít evident years ago.
Sometimes an item comes with multiple certificates. Why? The owner may be trying to improve the status of the item by having multiple good certificates issued.
Sometimes an item may have differences in the opinion rendered by two separate committees. Exceedingly rare, this does happen. For example, one committee may find an item to be genuine in all respects and another committee may find the same item to regummed. One of the committees is wrong because a stamp cannot possibly be full original gum and regummed at the same time.
Fees between committees are similar. Committees charge a minimum fee to expertise an item. For more expensive items, the fee is usually a percentage based on catalog value. You should first consult the policies and fees for the committee you want to submit the item to. If youíre interested in graded certificates, only the PF and PSE offer those. APEX does not currently offer graded certificates.
When does it make sense to obtain a certificate? There is no golden rule. In general items cataloging $100 or more may be candidates for certificates. A certificate adds value to an item. But the certificate has a cost. At a minimum charge of about $25, youíre not going to submit common material cataloging only a few dollars or less (unless youíre going for a graded certificate, but thatís a whole different story). Some items like rare coil issues are ripe with fakes. Any rare US coil issue should have a certificate.
A clean certificate should pay for itself. Suppose you submit the item for a certificate and the fee is $25. Assuming it gets a clean certificate, the item should be worth an additional $25 or more because it has a clean certificate. If you bought a $10 stamp and got a certificate on it, itís unlikely that the certificate will triple the value of that item to $35. As items approach the $100 or more in value range, then a certificate is more affordable and makes financial sense.
Beware of fake certificates. There have been instances of someone offering an item with a fake certificate. There was a recent instance of someone on eBay offering items with obviously fake APEX certificates. If you have any doubt whatsoever about the genuineness of the certificate, donít hesitate to contact the committee that issued the certificate. Youíll need the certificate number and the date of issue. The committees will assist you in verifying that the item has a genuine certificate. Security features are built in to try and eliminate the creation of fakes, but it does happen.
Beware of certificates with fake, but professional sounding names. Iíve seen instances on eBay where someone has a certificate from, for example, ďThe Professional Stamp FoundationĒ. Theyíre playing games to convince you that this is a legitimate certificate. Itís not.
Stamps change over time. Even though an item may have a certificate, the stamp may have changed after the certificate was issued. For example, a certificate may have come back for a stamp with no faults noted. But due to improper handling, the stamp may have developed a thin in the meantime. It happens. Just because an item has a certificate doesnít mean you donít need to still evaluate it. The certificate was correct at the time the stamp was examined. A certificate canít capture changes after the fact.
If a certificate was issued for a block/multiple of some item and that item is broken up, then new certificates should be obtained for each smaller piece. A photocopy of the certificate for the larger piece is meaningless because it is not an original. Photocopies of a certificate add nothing to the value of an item.
And lastly, make sure the actual stamp matches the picture on the certificate. Check the perforations and centering very closely. If there is a cancel, check that closely too. They should be identical. Make sure someone didnít substitute a faulty (or fake) stamp with a clean certificate for some other stamp. Virtually every stamp is unique in some way with the varying shape and contour of the perforations, etc. It is almost impossible to swap one stamp with the certificate for another stamp. If it doubt, a new certificate may be in order.
Certificates are a good thing. They provide some security that the item is genuine. The additional value they add to an item often times recoups the cost of the certificate. If you buy/sell in expensive material, certificates may be worth your consideration.