What is a Mule Coin?

 

What is a Mule Coin? | Mule Error Coin Overview

Believe it or not, the imperfection on your coin may actually be quite valuable. Mint-made error coins are coins that were improperly minted. Certain error coins can be worth a lot of money, depending on the type and obviousness of the error they feature. One particularly fascinating type of error coin is known as a mule coin. Mule coins are coins that have been mistakenly struck with another coin’s obverse or reverse. The result is a specimen that looks normal on one side and like a completely different coin on the other. 

Why are they called mule coins? Mule coins get their name from the mule, an animal that is born when a horse and donkey breed. Like the mules of the animal kingdom, mule coins are a combination of two different coins combined into one. Unlike some of the other common coin errors we see in numismatics, mule errors are typically quite obvious and easy to spot. Despite the name, the mule coin effect can also happen to privately minted silver and copper rounds. 

This page is a comprehensive guide to mule coins, including how to identify a mule coin, how much these error coins are worth, and more. 

Identifying a Mule Coin

Identifying mule coins is not particularly difficult – at least in most cases. A coin can be “muled” on either the obverse (front) or reverse (back), so mule coins appear to be normal until you examine both sides. For example, a mule Britannia coin may feature the normal Britannia icon on the reverse but another Royal Mint coin’s obverse. 

To see if a specimen is a true mule coin, take a look at its designs on both sides. Cross-reference these designs with a coin catalog to see if anything looks incorrect. If one side of your coin actually features a design that’s supposed to appear on another of that mint’s coins, you might have a mule coin on your hands! Mule coins can sometimes be confused with other types of mint-made errors. Usually, a mule coin won’t appear to be misshapen or heavily damaged by its errors. To the observer, a genuine mule coin will look relatively normal – except for the incorrect obverse or reverse artwork. 

Mule Coins Vs. Other Common Mint-Made Errors

Inexperienced or new collectors may sometimes confuse mule coins and brockage error coins. On a brockage error, a coin has been accidentally struck by another coin that was ‘stuck’ to the die during the minting process. The result is usually a coin partially or fully imprinted with a second obverse or reverse design in place of its original intended designs. Brockage coins are almost always deformed as a result of this error, and the reverse/obverse imprinting is a mirror of how the design is supposed to look. 

Mule coins can be differentiated from mule coins by looking for these deforming and mirroring effects. A proper mule coin will almost never be deformed, and its replaced obverse/reverse design shouldn’t be mirrored. This is because a mule error occurs when the dies are prepared; Mint workers create a mirror coin by accidentally combining two dies that are not meant to be combined. 

Additionally, mule coins combine the designs of two different coins, whereas the brockage effect involves the design of a single coin being ‘mirrored’ and duplicated onto the coin’s second side. 

Mule Coin Values 

The precise value of a mule error coin is difficult to assess for a variety of reasons. For one thing, mule coins can sometimes be very common. The Royal Mint accidentally created tens of thousands of mule coins when it produced the 2014 Silver Britannia Coin. Because so many of these coins entered circulation, they’re not particularly valuable on the secondary market. Other mule coins, especially circulating U.S. currency mule coins, can be quite valuable to collectors. 

Like with other error coins, the condition of a mule coin can also impact its value. This is especially true for circulating coins featuring the mule error effect. Very few of these error coins are kept in uncirculated condition for many years, making pristine specimens very valuable to collectors who specialize in mint-made error coins. 

“Spectacularness” also plays a role in the value of all error coins, including mule coins. This term refers to how obvious or unique the error appears. Certain mule coins feature incorrect obverse designs that are only marginally different than the designs that they were meant to have, making them less interesting to collectors. But mule coins with radically different reverse designs than they’re supposed to have can sometimes sell at a massive premium on the secondary collector market. 

Mule Coin Examples

Surprisingly, this minting error frequently occurs on privately minted rounds – not just government-produced coins! Mule errors can occur in bullion coins, rounds, and even in circulating U.S. coins like dimes, quarters, nickels, and pennies. Below, let’s take a closer look at two of the most fascinating mule error coins on the market in 2025. 

2014 Britannia-Lunar Horse Mule Coins

In 2014, the British Royal Mint announced that it had accidentally mixed up the obverse designs for two coins: the 2014 Silver Britannia and the 2014 Lunar Horse Silver Coin. As a result, as many as 38,000 Lunar Horse coins were mistakenly minted with an obverse design meant for the Britannia series. Thousands of Britannia coins were likewise given the Lunar Horse Coin’s obverse design. Mules from this series can be identified by looking for the denticle effect on the Lunar Horse or a lack of denticle effect on the obverse of the 2014 Silver Britannia. 

Provident Prospector V1 Silver-Copper Mule Round

A select number of Provident Metals’ Prospector Silver Rounds were accidentally struck with the reverse design meant for the 1 oz copper version of the same round. The obverse of each round is the same as intended, but the reverse side clearly reads “.999 fine copper.” Mule error versions of this round routinely sell at hefty premiums, like many privately minted rounds with the mule effect. 

Are Mule Coins a Good Investment? 

Investing in error coins can be a rewarding and exciting hobby, but it’s not for everyone. It takes quite a bit of knowledge and research for new collectors to understand what makes an error coin valuable, and reselling mint-made errors can be difficult for new and inexperienced investors. Still, knowing what to look for can help you expand your collection with rare and valuable coins or rounds. 

Because a mule error occurs before a coin is actually struck instead of during the striking process, these coins are generally rare to find in the wild. But when a mule error does occur, there’s usually a large number of coins/rounds minted incorrectly before the mint behind the coin is able to correct its mistake. That’s why the British Royal Mint produced tens of thousands of mule coins in 2014, and its why many mule coins aren’t worth nearly as much as full reverse brockages, spectacular doubled die errors, and other less common coin errors. 

Still, interesting mule coins with relatively limited mintages can sometimes be highly sought-after collector’s items. Ultimately, mule coins can be a good investment – if you’ve done your homework and know which mules to look out for! 

Final Thoughts: Identifying and Collecting Mule Coins

Mule coins are created when a mint accidentally uses another coin’s design when striking one side of a coin. The result is a mule, a combination of two coins. The mule error effect can appear on circulation coins, bullion coins, and even privately minted silver rounds. Collecting these coins can be a fantastic hobby, and spotting a mule coin is usually not particularly difficult. 

Ready to start adding some mule coins to your collection? 

• What Are Mint-Made Error Coins?
• Collecting Brockage Error Coins
• What is a Clipped Planchet Coin?