US Error Coins: The Fascinating Anomalies of Numismatics

Error coins (also called “mint-made error coins” or “mint error coins,”) are made incorrectly, often due to a mistake in the minting process.

A common coin error is an off-center strike, where the stamped design isn’t centered onto the coin.

Some famous error coins:

• 1955 Doubled-Die Lincoln Wheat Penny

• 1982 P-Roosevelt Dime

• 1942/1 Overdate Mercury Dime

• 1935 Double-Struck “DDR” Buffalo Nickel

• 1922 “No D” Lincoln Cent

• 1943 Double Die Obverse Quarter

• 2004 Extra Leaf Wisconsin State Quarter

Our team of international specialists is excited to share our industry knowledge about the different types of error coins, their rarity and value, and how to spot one.

Pictured above: Four off-center struck error Lincoln cents | Image credit: Doug coins, CC-BY-SA-4.0

Historical Background

Back when coins were hammered by hand, mistakes happened constantly.

Inconsistencies led to easier counterfeiting, so 16th-century European mints implemented milled (machine-made) coinage with screw presses. The coins were more efficient and detailed — harder to counterfeit.

Screw presses evolved into steam presses, eventually leading to automated electric presses used today.

Today, mints rate coins for defects, identify (and improve) error sources, and recycle most error coins before they’re circulated.

Types of Coin Errors

Most coin defects fall under one or more of the following categories:

• Planchet: Round metal disc ready to be struck as a specific coin; AKA “blank” or “flan”

• Die: One of two strong metallic stamping tools with inverse images, placed on either side of a coin before strike

• Strike: Process of pressing design (via dies) onto planchet

Now we’ll look at each category’s coin error lists.

Pictured above: Reverse of Jefferson nickel with lamination crack| Image credit: economic realist, own work, CC-BY-SA-3.0

Planchet Errors

In planchet errors, the planchet is wrong. It may be chipped, cracked, not thick or heavy enough, incomplete, or the wrong metal.

Types of planchet coin errors:

• Blank Planchet: Doesn’t go through the press, still circulated

• Wrong Planchet: Planchet fed into the wrong machine (e.g. penny planchet struck with quarter dies)

• Foreign Planchet: Planchet meant for foreign coinage struck with US coin dies

• Clipped Planchet: Not a complete circle because metal sheet misaligned in planchet-cutting machine; Clips can be straight, curved, or irregular

• Dirty Planchet: Design details dull or absent from oily/dirty planchet; Debris on planchet can cause extra lines in design

• Lamination Error / Split Planchet: Metal contaminant or internal stresses in planchet alloy make coin’s surface peel, discolor, or split

• Struck on Feeder Finger: Feeder finger (puts planchets into/out of press) struck with or instead of the planchet

• Transitional: Planchet of previous alloy struck as newly dated coin after mint transitions to new composition

One famous example of a valuable planchet error coin is a Georgia quarter die struck on a penny planchet… sold for $3,500!

Pictured above: Jefferson nickel with major die break (cud) error | Image credit: economic realist, own work, CC-BY-SA-3.0

Die Errors

Die errors happen when the dies are made incorrectly (pre-production errors), improperly installed into the press, or damaged during coining, either abruptly or over time.

Types of die errors:

• Die Crack: Crack in die transfers to coins, creating thin, raised line(s)

• Major Die Break (Cud): Cracks in die cause part of die to break off, creating coin with blank blob where die broke

• Die Clash: Planchet isn’t in collar to hold it in place, so top and bottom dies meet, leaving partial impression on each other; Coins pressed with clashed dies have “clash marks” – partial sunken, mirrored features (usually under 10% of design)

• Die Cap: Previous planchet in press doesn’t eject, new planchet put in, and first planchet sticks to coin die; Repeated strikes make first planchet bottle cap-shaped

• Die Alignment: Design tilted, rotated, or pivoted from misaligned dies

• Rotated Die: One die rotates, causing design to be oriented incorrectly (e.g. reverse & obverse both face north)

• Overdate / Overmintmark: Older error; New date/mintmark punched onto old die but coin shows remnants of old date/mintmark

• Mule: Coin struck with dies not meant to be used together; “Handsome” mules have 1 proof die and 1 business die

• Double (Doubled) Die (DDO or DDR): Images on coin are partially or fully doubled because the design on the die was misaligned; Can be on obverse (DDO) or reverse (DDR); Triple die (TDO or TDR) and quadruple die (QDO or QDR) also possible

• Repunched Mint Mark (RPM): Same mint mark letter (e.g. "D" for Denver Mint or "S" for San Francisco Mint) pressed twice but misaligned (different angles or different locations on coin); Only pre-1989 when mint marks were punched onto working dies

• Over Mint Mark (OMM): One mint mark struck over a different mint mark on same coin

Some well-known die errors are the “MAD clashes,” Lincoln cents from 1992 to 2000 with severe clash marks of at least 20 percent misalignment.

Pictured above: Nickel with brockage error | Image credit: Mudskippie, Public domain

Strike Errors

Strike errors happen when something goes wrong while the coin is being stamped in the press. Since there are more factors involved, many coin mistakes happen from strike errors:

• Off-Center Strike: Planchet improperly fed into press, causing off-center design

• Double / Triple Strike: Planchet struck multiple times because it doesn’t eject; Often confused with double die / triple die errors

• Die Adjustment: Low-pressure strike makes faint design because operator adjusts machine

• Strike-Through: Foreign object (e.g. hair, oil, staples) gets on planchet, leaving impression/embedment (“retained” strike-through) or breakage/complete split once coin is struck

• Broadstrike: Planchet is struck without being held in collar, so resulting coin has a larger diameter

• Partial Collar: Coin has malformed edge because the collar holding it isn’t fully engaged

• Brockage: Already pressed coin sticks to die and leaves mirror image onto the next coin pressed; If brockage (the mirrored-image coin) is then struck into a planchet, it's a counterbrockage

• Bonded Coins: Two coins (minted or planchets) pressed together & fused; More than two = “bonded pile-up”

• Double Denomination: Coin fed through multiple presses

• Struck Fragments: Metal fragments (debris or part of planchet) struck, stays in chamber, then gets struck with next planchet

• Fold-Over Strike: Planchet fed vertically, gets pressed on its edge & partially folded over; Z-fold or double foldover strike = opposite planchet ends have paraxial folds

Among these mistakes, off-center strikes are among the most common coin errors.

Pictured above: Lincoln cent with only partial date, likely caused by filled die| Image credit: economic realist, own work, CC-BY-SA-3.0

Other Errors

Many errors happen after the planchet is initially struck (post-strike).

Examples of other types of coin errors are:

• Ejection Impact Doubling (EID): Offset, sometimes scattered, raised design doubling when struck coin is pushed back into the retreating die

• Proof Errors: Various errors causing proof to not meet proof coin standards, like mismatched dies or incomplete special finishes

• Ejection Damage: Damage (e.g. scratches, scrapes) from feeder or ejector while coin is still in chamber after being struck

• Crenellated Rim: Longer vertical reeding (resembling picket fence) along coin’s edge formed when coin is pushed out of collar

Sometimes errors occur in the lettering on the coin’s edges, which are:

• Missing entirely

• Doubled or overlapped

• Misaligned

• Spaced incorrectly in the design

• Skipped (misspelling)

• Incomplete

• On the wrong planchet or unstruck planchet

• Too deep

• Smeared

• Chipped

So, which error coins are valuable?

Pictured above: Obverse and reverse of a 1943 Lincoln cent struck on bronze planchet instead of zinc-coated steel planchet | Image credit: Ira & Larry Goldberg Coins & Collectibles, Inc, Public domain

Rarity, Value & Collectibility

The value of an error coin depends on a few factors:

• Rarity: Rare error coins include ones that had lower mintage (fewer made), aren’t minted anymore, or simply have an error that rarely happens. Higher denomination error coins (like 50-cent and 1-dollar coins) may be more valuable than lower denominations (like 1-cent or 5-cent), since more lower-denomination coins are minted annually.

• Condition: Older error coins in good condition can retain higher value. The condition can also mean how dramatic the error is — a more dramatic error usually means higher value.

• Demand: Demand for certain error coins fluctuates over time, so their value can change depending on their current popularity.

Nowadays, modern coin errors are rare and valuable. Error collectible and investment coins like proofs are even rarer.

Find out if your coin errors are worth money by consulting a coin grading expert to assess its rarity and condition, then give you a numismatic value range based on current demand.

Pictured above: Obverse of 1955 doubled-die Lincoln cent. The reverse is not being uploaded as it is like any Wheat cent | Image credit: Lost Dutchman Rare Coins for image & Victor David Brenner for coin, Public domain

Popular Error Coins

Arguably the most famous: the 1955 double-die penny or “DDO Lincoln cent.” That year’s penny die was misaligned, so the obverse image was dramatically doubled in around 20,000 to 24,000 circulated pennies.

These valuable error coins can sell for $1,000 to over $125,000.

Another iconic error coin: the 1943 copper (bronze) Lincoln cent. World War II copper needs resulted in 1943 penny planchets being made from zinc-coated steel instead of bronze.

However, a few of these 1943 pennies were struck on leftover copper alloy (bronze) planchets. The 1943 bronze pennies have sold for $100,000 to $1.7 million! These error cents are similar to 1944 steel pennies meant to be struck from bronze, which are only slightly less rare; a 1944-S steel cent sold for $408,000 in 2021. 

The record-setting 1943-D bronze cent that sold for $1.7 million in 2010 was resold for $840,000 in 2021, though.

The current record-setting error coin is a 1958 DDO (doubled-die obverse) Lincoln cent, one of only three known, that sold for $1,136,250 in January 2023. 

Types of Error Coins Worth Money

Some coin errors will almost always carry significant value. Here are some valuable types of coin errors:

• Broadstrikes

• Overdates

• Overmintmarks

• Mules

• Fully Overlapping Brockage

• Double Denomination

• Wrong (Foreign) Planchet

• Double-Die

• Proof Error Coins

It’s important to have error coins authenticated to know they’re the real deal.

Pictured above: Clipped planchet error on Jefferson nickel | Image credit: economic realist, own work, CC-BY-SA-3.0

Detecting & Authenticating Errors

Certain coin errors are easier to fake, such as:

• Edge strikes

• Strike-throughs

• Clipped planchets

Popular error coins may be counterfeited more, like the double-die 1955 wheat pennies. Only 40,000 were minted and around 15,000 are known today, but counterfeiters have tried to DIY them for a quick buck.

One key sign of fake double-die coins is an impressed (not raised) image.

To authenticate error coins, join online coin collector forums to know if your error coin is worth having assessed. Two highly reputable third-party agencies are PCGS (Professional Coin Grading Services) and Numismatic Guaranty Company (NGC).

The cost of having your error coin graded depends on its maximum resale value. A maximum $300 value coin can cost around $20 to grade, while a maximum $10,000 value coin can cost around $70 to grade.

On the hunt? Here are tips for finding error coins:

• Be patient

• Know what to look for

• Carefully look through each coin in pocket change, coin rolls, or coin lots

• Check estate sales and coin shops

Of course, you can also find error coins from the comfort of your own home by exploring the error coins available here at Coins Auctioned!

Pictured above: Flip-over multi-struck Lincoln cent | Image credit: economic realist, own work, CC-BY-SA-3.0

One Mint’s Mistake is a Coin Collector’s Treasure!

If you’re looking to add some error coins or other unique coins to your collection, you’re in the right place.

Buy unique and collectible coins today!