The US mint marks and their mints
The United States has operated several branch mints over its history, each marking its coins with a letter. Philadelphia, the main mint, traditionally used no mark at all; its P mark appeared on wartime nickels in 1942–45 and became standard on most denominations from 1980 onward (the cent remained unmarked).
- No mark or P: Philadelphia, Pennsylvania (1793–present)
- D: Denver, Colorado (1906–present)
- S: San Francisco, California (1854–present, mostly proofs today)
- CC: Carson City, Nevada (1870–1893) — always collectible
- O: New Orleans, Louisiana (1838–1909)
- W: West Point, New York (bullion, commemoratives, and some special issues)
- C (Charlotte) and D (Dahlonega): gold coins only, 1838–1861
Where to find the mint mark
Location varies by series and era. On modern US coins the mark sits on the obverse near the date. Older series hid it on the reverse: below the wreath on Morgan dollars, below the branches on wheat cents (D and S only), right of the building on Jefferson nickels, and near the bottom of the reverse on Mercury dimes.
From 1965 to 1967 US coins carried no mint marks at all, a deliberate move during the coin shortage era. Use a loupe — worn or small marks are easy to misread, and misreading an S for nothing has cost people real money.
Why the same date can differ wildly in value
Branch mints often struck far fewer coins than Philadelphia, so the mint mark frequently determines rarity. A 1916 Mercury dime from Philadelphia is common; the 1916-D, with just 264,000 struck, is a famous key date worth hundreds even in low grades.
Carson City coins carry romance premiums beyond their mintages thanks to their Old West origin. Because small letters are easy to fake, added or altered mint marks are a classic counterfeiting trick — key-date mint-marked coins deserve authentication.
World mint marks in brief
Most countries use mint marks or privy marks too: a letter A for Paris on many older French coins, letters A through J (and beyond) for German mints past and present with A for Berlin and D for Munich, and small symbols like Canada’s maple leaf privy marks or Mexico City’s Mo monogram — one of the oldest marks in the Americas.
Catalogs such as the Standard Catalog of World Coins and Numista list mint marks and mintages for nearly every issue, which is how you check whether your mark is the scarce one.
Let CoinVault Pro read the fine print
Not sure what that tiny letter is, or whether it matters? Scan the coin with CoinVault Pro: the AI identifies the exact issue, and the live value data — drawn from Numista’s catalog and real eBay sold prices — immediately shows whether your mint mark is the common one or the one collectors chase.
It is an easy habit that catches sleepers: same date, different mint, very different price.