Error coins are coins that have been miss-produced at the mint.

Most should have been spotted at the mint before being released into circulation,
therefore, all tend to be relatively rare.  

Some error coins depending on the type of error are extremely rare. Gold ones
tend to be amongst the rarest because they are the coins that are more closely
inspected by the mints.  

Error coin collecting is a more specialised coin collecting subject and although
initially error coins were scorned at by collectors, the popularity for collecting them
has increased over the recent years.

Below are several different types of major error coins.
Broadstruck Error
Brockage Error
Blank Planchet Error
Clipped Planchet Error
Die Cap Error
Doublestruck Error
Off Centre Error
Thick & Thin Planchet Error
Wrong Planchet Error
Multiple Error
Struck Through Scrap Error
Struck On Scrap Metal Or Other Objects
Rotated Die Error Coin
TO ERRor IS HUMAN, TO COLLECT DIVINE written by Scott Wren

This article first appeared in the August 2015 issue of COIN NEWS

There are a vast array of what are in some cases extraordinary, if not unique—yet in my opinion, undervalued—
“errors” that exist on UK Hammered, Milled, Pre-Decimal and Decimal coins alike. I say “unique, yet….undervalued”
as the rather meagre prices these UK “errors” predominantly fetch at auction or via retail sales—one of the key
indicators of collectability—are for the most part well below what similar US, Australian, Canadian and Euro “error”
examples would realise.

Before delving into this subject any further, it might be prudent to briefly recap these “fundamental differences”
between an “error” and a “variety” for the benefit of those that haven’t had the opportunity to read the
aforementioned articles (shame on you!). In a literary-cum-professional sense, it goes against my better judgement to
self-quote my own definition of these differences but it is a necessary evil in order to clarify the “error”-vs-“variety”
debate. The following definitions are drawn from my Coin News article of January 2015; “The Truth Behind the
‘Legend Error’; Part I”:
“…a ‘variety’—as the anomalous feature usually happens at a given point in the exhaustive die preparation phase—
will be repeated on any number of coins struck with that same anomalous die.”
“…an ‘error’ occurs randomly at the time of striking, and as a result of this randomness, is usually a one of a kind
thing i.e. no two coins are alike; they may be very similar in appearance, but they are nevertheless different, if not

The key difference between an “error” and a “variety” I wish the reader to grasp, is the uniqueness of the
characteristics of an “error” in comparison with the ubiquitous nature of the “variety”. It is this “uniqueness”, this
individuality, which by all rights should bring about an enhanced collectability, and therefore, an increased value.
However, in order to embrace this rationale, it requires that any potential collector already understands why they
have to—and mind the pun here!—throw good money after bad for a coin that for all intents and purposes, some
consider to be essentially damaged. This unsympathetic opinion, however misguided, contradicts the time-honoured
numismatic convention to strive to attain perfection in the form of an “as struck” coin…not a “damaged” one. But this
notion of “as struck” relates purely to grade, and “grade” is often irrelevant in the case of individual “error” examples,
because aside from being “unique” and often without comparison; sometimes they are barely distinguishable as a
specific, identifiable coin, as clearly seen by the “error” Penny in Fig.1.

                         Fig.1 GB ND 1p Struck on Scrap Metal (courtesy Hus Sulo.

In dismissing from any discussion the notion that “errors” are fundamentally “damaged” coins and therefore have no
place in the world of collectable coins, you only have to look at their numismatic stable mate, the misprinted “error”
banknotes, to acknowledge that these so-called “damaged” examples are highly collectable and highly sought after,
and as such attract substantially greater values. And numismatics is not the only collectable discipline where a
production process error has resulted in a highly collectable item; the philately world has that famous U.S. stamp, the
“Inverted Jenny” of 1918, which erroneously exhibited an upside down bi-plane—it consistently sells for a six-figure
sum on the brief occasions it is offered for sale.
So, if “errors” in the production process of other collectable fields, like banknotes and stamps, results in increased
values; one has to wonder why there is a tangible degree of ambivalence toward “error” coins by a significant
element of UK based collectors?

Owing to the fact that I live in Australia, where “errors” are very much appreciated in the local numismatic community,
I have arrived at the aforementioned conclusion, not solely based on the marginal strength of the prices realised for
UK “errors”, but through reading a significant number of posts on online numismatics forums that concern the
collectability of UK “error” coins, and “errors” in general. A substantial portion of these comments subscribe to the
previously discussed view—however misguided—that such coins have no collectability or enhanced value as they are
simply “damaged” coins. However, another common thread, one that is equally disconcerting, seems to centre on the
belief that “error” coins are not the result of a random breakdown in the coining process but are man-made and
deliberate! The conjecture prevails that they have been legitimately struck in error and detected by the mint’s quality
control mechanisms…but then duplicitously removed from the mint by felonious staff. An even more illogical take on
this misguided viewpoint by some “error”-knockers is that they have been purposely struck, and then duplicitously
removed in a similar fashion. I find it hard to believe that any of the mint staff would risk their jobs, and their freedom
for that matter, for what would be a disproportionate reward—if UK “errors” realised the kind of prices their US and
Aussie cousins achieve then you might be able to make a believer out of me!

Fig.2 ROME (c.A.D.218-222) SILVER DENARIUS OBV Brockage (courtesy Noble Numismatics. Sale 98, Lot 5414)

If you look back to the very early history of minting coins, you will see that throughout the ages “error” coins occurred
and subsequently made it into circulation. Numerous examples of Ancient and Hammered “error” coins are regularly
offered for sale, and yet an analysis of the simple hand-struck process involved in their coining, highlights the reality
that any production process is prone to breakdowns at some point. Ancient and Hammered coins were hand-struck
by the “moneyors” using two separate tool and die combinations: the Pile, usually the bottom die, had a spiked end or
tang to support it in an upright position; and the upper die, the Trussel, had a mushroomed end for taking hammer
blows.  Given this straightforward method of striking coins, it’s very easy to fathom how certain “errors” on Ancient
and Hammered coins might occur. It would only take the moneyor—given the repetitive, hands-on nature of their
work—to momentarily lose concentration and an “error” coin is born. A moneyor might fail to remove an already
struck coin, strike a second erroneous blow, and the resulting “error” would be a ‘double-strike’, as shown in Fig. 5;
or, they might inadvertently set a second blank/planchet onto the Pile where a previously struck coin still rested,
strike a blow, and the result would be a ‘brockage’ as shown in Fig.2 & Fig.3.

   Fig.3 GB Charles II, Maundy penny (1679-84) full OBV Brockage (courtesy Noble Numismatics. Sale 107, Lot 91)

Therefore, if the simplistic, hands-on coining process used to strike Ancient and Hammered coins can result in
“errors” occurring, and considering that the “quality control” measures consisted of non-mechanical, human
accountability and was the responsibility of the moneyors themselves, then in the age of the mechanised mint
process which lacks such conscientious human supervision, then it’s totally plausible that such a bizarre array of
seemingly inconceivable “errors” exist today.

So, once again I will re-visit the question I posed earlier as to what are the reasons for this manifest antagonism and
suspicion on the part of various UK collectors in respects to the collectability of their own UK “error” coins? I do so in
the hope that those who shared this opinion at the outset of the article have absorbed some of the points I’ve made
so far and are now starting to question their initial scepticism…well, that is my hope anyway! If you are still standing
firm, and in no way swayed by my arguments thus far as to the collectability of UK “error” coins, then it might come as
a shock to hear me say that I understand where this scepticism comes from. Some “errors” that have surfaced are
ostensibly implausible and the only explanation for their existence is that they were deliberate and “manmade”.
However, I put any such viewpoint down to an entirely blameless lack of understanding and insight in regards to the
legitimacy of the origins of some of the more bizarre examples. To clarify this argument I will go straight to the source
and reference the fact that in recent years, the staunchly guarded, publicly perceived veneration for the Royal Mint’s
“quality control” practices has taken a hit of late. They have had to openly admit that “errors” do occur, and that they
make it into circulation despite their best efforts. Their very public acknowledgement of the ND (2008) 20p and the
2014 £2 1oz LUNAR/BRITANNIA ‘Mule’ are of significant note, yet represent but a few cases. I can recall seeing a
number of examples going back decades, of “letters of verification” from the Royal Mint, to individuals who’d
submitted “error” coins to the mint for their expert opinion. An example of just such a letter can be seen on the

The Royal Mint doesn’t stand alone in having to eat humble pie; its progeny, The Royal Australian Mint (RAM), has
also publicly acknowledged that mistakes are made which result in “errors” occurring, and reaching circulation. In
September, 2011 they addressed the issue head on and took this “public acknowledgement” to a whole new level
when they held a road-show exhibition called “One in a Million: Treasures from the Royal Australian Mint” which was
solely dedicated to mint “errors”. Perhaps the legitimacy of the collectability of “errors” is best summed-up by the RAM’
s very own official words in respects to the “errors” they put on display: “…collectors, would realise the value in such

The underlying reality when trying to verify the authenticity of an “error” coin in this, the age of the modern, highly
mechanized and sophisticated mint, comes down to some simple guiding principles. There are a number of these
guidelines but of key note are: the specifics of the blank/planchet of the “error” itself; and, the operational reliability of
the mechanised equipment involved in the coining process. For the sake of clarification of the key role these
aforementioned guiding principles play, a closer look at the genesis of some examples of major “error” types will
hopefully achieve this. If a 1p blank/planchet should inadvertently find its way into a hopper destined for the striking
of 2p pieces, then as it is smaller in dimension, it will readily (but rarely) fit into the larger 2p collar, and upon being
struck the result is an example of a 2p on 1p ‘wrong planchet’ “error” as shown in Fig.4.
Alternatively, a breakdown in the mechanical synchronization of the presses, in particular the feed/ejection and collar
components, are the root cause behind “error” types such as: the ‘off-centre’; the ‘double-struck’ (see Fig.5); and the
‘brockage’ (see Fig.2 & Fig.3), to name but a few. I know that for some readers, the latter examples are a little light in
the details department. So, in lieu of a more in-depth article with pictorial examples at some point in the future, I
suggest you access the wealth of information available on the subject, in both hard-copy format and
online…Wikipedia is a good starting point.

                                            Fig.4 GB 2006 2p on 1p ‘Wrong Planchet’ Error

Hopefully by this stage in proceedings any doubts you may have had in respects to the collectability of “errors” have
been mitigated to some degree. With this newfound appreciation for the legitimacy of the “error” coin in respects to its
humble origins, the next hurdle to surmount is addressing this inherent lack of appreciation in the UK numismatic
community for their own UK “error” examples.

This inherent ambivalence I allude to becomes apparent in the wider market when you consider the offerings/sales of
UK “error” coins on that modern day auction tool that is eBay. Indeed, you need only scour through the eBay listings
for such coins and you will see American, Australian and Canadian sellers, amongst other nationalities, offering UK
“errors” at listing prices comparable to examples of their own country’s “error” coins. Truth be told…they may take a
little longer to sell at these prices, but at least the seller appreciates their inherent value despite the ambiguous
antagonism they endure from their own British kinfolk.

                             Fig.5 GB ND 6d ‘Double-Struck’ Error (courtesy The Day Collection)

All things considered, just what it will take for UK numismatists, collectors and dealers alike, to wholeheartedly and
unanimously embrace UK “errors”, and appreciate them for their “uniqueness”, well…that is an unknown quantity. No
doubt the numismatic market will play a big part and influence trends. As sales of UK “errors” start to realise ever-
increasing values, so will their collectability follow a similar direction. For the novice UK “error” collector now is the
time to get in at ground level before the penny drops (yet another pun…sorry!). Educating yourself with the
minting/coining process from planchet through to the finished coin is a good start, and will assist you to work out for
yourself the inherent “rarity” of individual “error” types—unlike its non-“error” counterpart, grade is usually of little
significance, see Fig.1 for validation of this fact.
All is not lost though. Some 15 years ago the vibrant Australian “error” market of today was but a shadow of its
current self…and compared to the US market it was entirely unassuming. Yet over time, it grew and expanded, and
with each passing auction more and more “errors” appeared in the catalogues of the major auction houses. Whereas
in the past they were either ‘passed-in’, or at best, sold for less than the conservative estimates they were listed at, in
recent years they have attracted some serious bidding wars that have resulted in record breaking prices being
realised for some of the more major “errors”. The key is to take it slowly, let things run their natural course, and don’t
get dejected by the slow grind that unfortunately is the reality of breaking down the barriers to wholesale “error”
recognition and acceptance.

I’m going to bring this editorial to a close with a very fitting quote, as this affords me the opportunity to incorporate
into my argument the discerning words of someone whom played a significant part in the numismatic history of the
Royal Mint, Sir Isaac Newton. The famous scholar and former Warden of the Royal Mint and Master of the Mint,
around the turn of the 17th century is quoted as saying:

“If I have seen further it is by standing on the shoulders of giants”

The commonly accepted interpretation of the great man’s quote translates to “discovering truth by building on
previous discoveries”. I would like to believe that given his close association with the Royal Mint and numismatics in
general, Newton might just have summed-up the point I am trying to make in one sentence. In order to enhance the
collectability of UK “errors”, and develop the UK “error” market, perhaps some lessons can be learnt from established
markets such as those that exist in the US and Australia.

The Mint. A History of the London Mint from A.D. 287 to 1948. Sir John Craig. 2010 Paperback Edition. Cambridge
University Press 1953.

The Australian Coin Collecting Blog. An Explanation for Partial Collar Coin Errors; 15th June 2013. website found at:

MINT ISSUE Magazine, Issue 92; “From the Vault”, January 2012, pg 31. online source:

Noble Numismatics. Sale 98, Lot 5414; Sale 107, Lot 91.
Website with auction archive found at:

Hus Sulo. Website URL found at:

The Day Collection