The History of UNC, BU, Proof etc

The meanings and background of UNC, BU, Proof and others:

The old definitions (pre approx. this century)

‘UNC’ or Uncirculated is a well established but always a controversial numismatic term. It literally means un-circulated, i.e. a coin that has not previously been circulated. For many years it was accepted in numismatic circles that an uncirculated coin should have absolutely no wear on it whatsoever. The lustre wasn’t really a major factor (to most – a small minority of dealers still ascertain that UNC should mean full lustre, too). The odd minor bag mark, minor stain, toning, slight fault during production etc was acceptable on an ‘UNC’ coin, but any wear whatsoever rendered a coin not uncirculated and therefore within the ‘EF’ (extremely fine) grade range. Most coin dealers are still happy to call a completely unworn coin uncirculated. The reason the term is controversial and that some dealers/establishments are trying to move away from using it is that it’s misleading and doesn’t necessarily literally mean uncirculated – for older coins all it basically means is that the coin was whipped out of circulation quick enough for it not to have been worn in any way and has been kept very safe since then. The terms ‘virtually as-struck’ and ‘as struck’ are being used as alternatives and may well end up replacing ‘UNC’ in the future.


In the 1970s the terms ‘BU’ and ‘Gem BU’ were certainly in use in the USA, so it’s very probably that ‘BU’ and co. originated there. In the UK the term ‘BU’, or Brilliant Uncirculated is likely to have been introduced by the Royal Mint, who in the early 1980s designated their annual uncirculated year-sets as ‘Brilliant Uncirculated’ to make them sound a bit more exclusive. At that time the coins in the sets were (as far as I can tell) struck in exactly the same way as the coins that were made for circulation (sometimes called ‘business strikes’ – another US term) albeit they were slightly better handled and carefully sealed into packages.

In the UK the term ‘BU’ also caught on with dealers of older coins as it was useful to clarify the confusing situation with the term ‘UNC’ (to some it just meant unused and to others it was unused but had to have full mint lustre). ‘BU’ became the accepted and most popular UK nomenclature for an unused coin will full mint lustre (or ‘brilliance’). Dealers of older coins still use the term to refer to any coin, even quite old ones, that have miraculously managed to survive without showing any signs of use or any loss of lustre.

To complicate matters, silver coins tend to tone naturally over time and an old unworn but naturally toned silver coin is generally preferred over a bright one, as bright ‘white’ silver surfaces often indicate that a coin has been dipped, cleaned or in some way manipulated. Base metal coins (i.e. copper, bronze, brass or cupro-nickel) tone too, but are generally preferred untoned, when available, so the term BU is something you see being used more often for base metal coins than for silver ones. Gold tends to stay quite bright and for that reason some dealers avoid the term ‘BU’ in relation to older gold coins.


Originally a proof was genuinely a proof in the true sense of the word. Like a printers’ proof, i.e. something to be checked before being put into production. Early proofs were often presented to VIPs for approval before the main production began. Much time and care was taken in their production; they were struck onto specially prepared blanks and with specially prepared dies. Sometimes they didn’t enter production and therefore some coins only exist as proofs (so are technically patterns, see below). From the mid 19th century some proof coins were made available to the public and from the 20th century very often proofs were given to visiting statesmen and are usually called ‘VIP proofs’. Proofs were struck in very low numbers and they certainly weren’t mass produced every year, like they are today.

The term ‘cameo’ which originated in the USA, is sometimes used to denote a coin which possesses a very clear contrast between the frosted design elements and the mirror like fields (the flat bits). Older proofs didn’t always have frosted devices in this way. Proof coins that have either been slightly used (i.e. seen circulation) or have been damaged in some way are often called an ‘impaired proof’ and obviously the potential value is lower, depending on the extent of the damage.


A pattern is a coin usually struck to proof standards that did not eventually go into production as a circulation coin. Often a few different designs or sometimes different metal alloys were tried out and actually made into coins before the final design/alloy combination was selected for production.


Sometimes the abbreviation ‘FDC’ may be seen in connection with coins. Not to be confused with the stamp collectors’ ‘First Day Cover’! It’s an old French term hardly used nowadays that means ‘Fleur de Coin’ and denotes a coin that is absolutely perfect in every way, something which very few coins can ever hope to achieve. Technically an ‘FDC’ coin can be any type of coin but realistically the manufacturing standards and the way coins are mass produced means that only proof coins (that are made and treated better) come in to contention of being truly FDC.

The Modern definitions:

Language evolves and so have the precise meanings of some numismatic terms.


‘UNC’ remains controversial but is falling out of favour with the new generation of modern coin collectors. Lots of people are of the opinion that uncirculated really should mean un-circulated, so that rules out any coins found in change (no matter how early on in their lives), as they are technically circulated.

To most decimal coin collectors these days there are only three widely used grading terms: ‘Used’ or ‘circulated’, ‘BU’ and ‘Proof’. The old range of grades from Poor to FDC don’t seem to apply to modern coins.


The meaning of BU has shifted in recent years from denoting the grade (state of preservation) of a coin – potentially achievable by any type of coin that was safely stored away very early in its life – to becoming a new striking standard; a completely new product altogether. The Royal Mint state that BU coins (i.e. the coins they sell in their BU sets and single packages) are struck to higher standards than circulation coins.

Also, quality control for the circulation coins the Royal Mint strike has fallen drastically in the last 15 years or so. Freshly made coins, even coins sealed in bags, are invariably of inferior quality, whereas in the past, often 20% or more of coins struck for circulation would have qualified as a problem free BU coin. This recent decline in quality is not only due to the way they seem to be man-handled after they are made, but in actual fact is mainly due to the appalling state of the dies that are used to produce them, which are allowed to strike coins well after the point at which they should be retired – the dies often have cracks or breakages resulting in cuds (blobs), raised lines and other defects. Bi-metallic circulation coins (the £2 coin and the new £1) often have burnt on grease marks, filled-in detail and are not properly centred. Nowadays the only way to get a near-perfect coin is to buy it in a year set or a sealed package from the Royal Mint (and even those can sometimes be less than perfect).


Used to be something special but is now basically a commercial product, mass produced and sold mainly in year sets but also in precious metal guises as single coins or sets of coins and often in upteen different types of package. The good thing about modern proof coins is that they are generally very well made and can be the best way to appreciate high quality coins. In you buy a proof coin new and it isn’t absolutely perfect to the naked eye at least, send it back!


Originally a coin featuring a new design or an altered metal composition that was a contender to be mass-produced but didn’t make it all the way into production. In recent times the term has been used on a couple of occasions by the Royal Mint in conjunction with proof coins featuring designs that either were or were not issued as circulation coins! Modern ‘pattern’ coins are essentially a sales gimmick and usually feature the word ‘PATTERN’ in place of the denomination (something that didn’t feature on genuine older pattern coins). In the past private companies and individuals have also produced pattern coins usually in the hope that they would be officially selected for production or retrospectively as fantasy pieces for commercial purposes.

CHP, 20th July 2017

The images on this page are, from top to bottom: an UNC 1959 florin, a BU 1968 Irish penny, a proof 1831 shilling and a pattern 1870 penny featuring the Queen with a coronet, which never went into production.