After buying and selling coins for about a year on e-bay, I discovered that the grading service that goes by NNC (National Numistmatic Certification) would be better named NEVER NOTICES CLEANED coins. I have sent several NNC graded coins to PCGS & ANACS for regrading and they all have been returned as Altered Surfaces (by PCGS) and graded as Cleaned coins by ANACS. Apparently NNC is a grading service of last resort if you have a good quality coin you want graded but the coin shows some evidence of cleaning, waxing, hazing, thumbing, etc. (see pcgs.com for a glossary of terms).

PLEASE NOTE, even small evidence of cleaning or altered surfaces can prevent a very beautiful coin from achieving the price it would otherwise justify based on it's grade. Cleaning can be found even if an uncirculated coin is wiped only lightly with a soft cloth.  I agree with NNC that a beautiful coin should not be penalized for slight signs of cleaning. However, the fact of life in the collecting world is that the market does not have the same relaxed attitude toward cleaned and altered coins. At least one of the reasons for this is the difficulty in establishing an accurate grade for coins that have altered surfaces or have been cleaned. In no small part many of the alterations are made for the specific purpose of improving or misleading the grading of the coin by inexperienced collectors.

I have noticed that many NNC coins have great eye appeal but invariably show more surface blemishes for the grade assigned than PCGS, NGC, ANACS, or ICG. Also, NNC suffers from one of the same problems all second tier grading services suffer from, I like to call it "Grading Creep". What this means to me is that common date coins are frequently graded, by second tier grading services, within two or three grades of the top tier grading services, but "Grading Creep" starts with the rarer date coins. With the results that the key dates and top rarities in a coin type are frequently overgraded by four, five, or even more grades.

AVOID RARE DATE COINS GRADED BY NNC. You might think their MS66 coin has got to be at least an MS60. Wrong see my guide "coin grading services are not all equal".

In the case of some grading services, their grading is totally useless.  If you feel you must bid on the coins graded by the following DOGS, you should reduce the graded by more than five grades AT LEAST. The DOGS include HCGS, SGS, GEC, NAC,and INB. While this is not a complete list these are some of the worst. And even a discount of 5 grades might not be enough on super rare dates.

Please see my other guides: "All Coin Grading Services are not Equal" and "Peace Dollars versus Morgan Dollars. If this guide was helpful, please click Yes below.