One pound (British coin)

Original round coin.

New 12-sided coin.

To date, four different portraits of Elizabeth II have appeared on the obverse. For the first three of these, the inscription was ELIZABETH II D.G.REG.F.D. 2013,[14] where 2013 is replaced by the year of minting. The fourth design, unveiled in March 2015,[15] expanded the inscription slightly to ELIZABETH II DEI.GRA.REG.FID.DEF. 2015. The 12-sided design, introduced in March 2017, reverted to 2017 ELIZABETH II D.G.REG.F.D.

In summary:

• In 1983 and 1984 the portrait of Queen Elizabeth II by Arnold Machin appeared on the obverse,[16] in which the Queen wears the "Girls of Great Britain and Ireland" Tiara.
• Between 1985 and 1997 the portrait by Raphael Maklouf was used,[16] in which the Queen wears the George IV State Diadem.
• Between 1998 and 2015 the portrait by Ian Rank-Broadley was used,[16] again featuring the tiara, with a signature-mark IRB below the portrait.
• In 2015 the portrait by Jody Clark was introduced,[17] in which the Queen wears the George IV State Diadem,[18] with a signature-mark JC below the portrait.

The Royal Shield formed by six UK coins, with the £1 coin depicting the whole of the shield.

In August 2005 the Royal Mint launched a competition to find new reverse designs for all circulating coins apart from the £2 coin.[19] The winner, announced in April 2008, was Matthew Dent, whose designs were gradually introduced into the circulating British coinage from mid-2008.[20] The designs for the 1p, 2p, 5p, 10p, 20p and 50p coins depict sections of the Royal Shield that form the whole shield when placed together. The shield in its entirety was featured on the £1 coin. The coin's obverse remained unchanged.

The design of the reverse of the original coin was changed each year from 1983 to 2008 to show, in turn, an emblem representing the UK, Scotland, Wales, Northern Ireland, and England, together with an appropriate edge inscription. This edge inscription could frequently be "upside-down" (when obverse is facing upward).[21] From 2008, national-based designs were still minted, but alongside the new standard version and no longer in strict rotation. The inscription ONE POUND appeared on all reverse designs.

In common with non-commemorative £2 coins, the round £1 coin (except 2004–07 and the 2010–11 "capital cities" designs) had a mint mark: a small crosslet found on the milled edge that represents Llantrisant in South Wales, where the Royal Mint has been based since 1968.[22]

The reverse of the new 12-sided, bimetallic pound coin, introduced on 28 March 2017,[5] was chosen by a public design competition.[23] The competition to design the reverse of this coin was opened in September 2014.[24] It was won in March 2015 by 15-year-old David Pearce from Walsall, and unveiled by Chancellor George Osborne during his Budget announcement. The design features a rose, leek, thistle and shamrock bound by a crown.[15]

Current £1 coins are legal tender to any amount.[25][26] However, "legal tender" has a very specific and narrow meaning which relates only to the repayment of debt to a creditor, not to everyday shopping or other transactions.[27] Specifically, coins of particular denominations are said to be "legal tender" when a creditor must by law accept them in redemption of a debt.[28] The term does not mean – as is often thought – that a shopkeeper has to accept a particular type of currency in payment.[27] Shopkeepers are under no obligation to accept any specific type of payment, whether legal tender or not; conversely they have the discretion to accept any payment type they wish.[26]

During later years of the round pound's use, Royal Mint surveys estimated the proportion of counterfeit £1 coins in circulation. This was estimated at 3.04% in 2013, a rise from 2.74%.[10][11] The figure previously announced in 2012 was 2.86%, following the prolonged rise from 0.92% in 2002–2003 to 0.98% in 2004, 1.26% in 2005, 1.69% in 2006, 2.06% in 2007, 2.58% in 2008, 2.65% in 2009, 3.07% in 2010 and 3.09% in 2011.[41][42] Figures were generally reported in the following year; in 2008 (as reported in 2009), the highest levels of counterfeits were in Northern Ireland (3.6%) and South East England and London (2.97%), with the lowest being in North West England.[43][44][45] Coin testing companies estimated in 2009 that the actual figure was about twice the Mint's estimate, suggesting that the Mint was underplaying the figures so as not to undermine confidence in the coin.[46] It is illegal to pass on counterfeit currency knowingly; the official advice is to hand it in, with details of where received, to the police, who will retain it and investigate.[47][48] One article suggested that "given that fake coins are worthless, you will almost certainly be better off not even looking".[46] The recipient also has recourse against the supplier in such cases.

Counterfeits are put into circulation by dishonest people, then circulated inadvertently by others who are unaware; in many cases banks do not check, and circulate counterfeits. In 2011 the BBC television programme Fake Britain withdrew 1,000 £1 coins from each of five major banks and found that each batch contained between 32 and 38 counterfeits; the Mint estimated that about 31 per 1,000 £1 coins were counterfeit.[47] Some of the counterfeits were found by automated machinery, others could be detected only by expert visual inspection.

In July 2010, following speculation that the Royal Mint would have to consider replacing £1 coins with a new design because of the fakes, bookmakers Paddy Power offered odds of 6/4 (bet £4 to win £6, plus the £4 stake back; decimal odds of 2.5), that the £1 coin would be removed from circulation.[44][49]

Real and fake round pound, showing poor-quality edge inscription and milling, and colour difference.

Some counterfeits were of poor quality, with obviously visible differences (less sharply defined, lacking intricate details, edge milling and markings visibly wrong). Many better counterfeits can be detected by comparing the orientation of the obverse and reverse—they should match in genuine modern UK coins, but very often did not in counterfeit round £1.[47][48] The design on the reverse must be correct for the stamped year (e.g., a 1996 coin should have a Celtic cross).[50] It was difficult to manufacture round pounds with properly-produced edges; the milling (grooves) was often incomplete or poor and the inscription (often "DECUS ET TUTAMEN") sometimes poorly produced or in the wrong typeface.[47] A shiny coin with less wear than its date suggests is also suspect, although it may be a genuine coin that has rarely been used.[48]

Counterfeit coins are made by different processes including casting, stamping, electrotyping, and copying with a pantograph or spark erosion.[51] In a 2009 survey, 99% of fake £1 coins found in cash centres were made of a nickel-brass, of which three fifths contained some lead and a fifth were of a very similar alloy to that used by the Royal Mint. The remaining 1% were made of simple copper-zinc brass, or lead or tin, or both.[52] Those made of lead or tin may have a gold-coloured coating; counterfeits made of acrylic plastic containing metal powder to increase weight were occasionally found.[51]

The final 'round pounds' were minted in December 2015; the replacement, a new 12-sided design, was introduced in 2017,[53] the earliest dated as 2016. The coin has a 12-edged shape, similar to the pre-decimal brass threepence coin; it has roughly the same size as the previous £1 coin, and is bi-metallic like most £2 coins. The new design is intended to make counterfeiting more difficult, and also has an undisclosed hidden security feature called "iSIS" (Integrated Secure Identification Systems),[23][54] thought to be a code embedded in the top layer of metal on the obverse of the coin, visible only under a specific wavelength of ultraviolet light.[55]

Current two-pound coins, being bi-metallic (excluding some rarely tendered commemorative issues), remain harder to counterfeit than the round pound was; such counterfeits would often easily seen to have wrong colours.

While the round pound was operational, others that entered circulation, although not legal tender in the UK, were some £1 coins of British Crown Dependencies, Gibraltar and UK South Atlantic Overseas Territories. Most coins of these territories, in all denominations, were of the same size and composition as a UK equivalent and most bore the same portraits of the UK monarch.[56][57] After the UK replaced its round pound coins, none of these territories rushed to do so, except Gibraltar, which continues to use Gibraltarian pound coins as legal tender as well as the new UK pound coins.

In an April 1993 The New Yorker article "Real Britannia", Julian Barnes describes the meetings to choose the 1994–1997 reverse designs.[58] This is reprinted in his book Letters from London as "Britannia's New Bra Size".

• Banknotes of the pound sterling
• Coin counterfeiting
• Coins of the pound sterling
• Sovereign — gold coin with a (nominal) value of £1

• Royal Mint – £1 coin
• Royal Mint – the new pound coin
• One Pound, Coin Type from United Kingdom – Online Coin Club