Change FinderUK coin error checker — errors worth money
UK coin error checker — errors worth money — checked and valued for 2026. From the 25 Pence 'EXPERIMENTAL COIN 1981 / ROYAL MINT TRIAL' seven-sided trial piece down, here are the coins actually worth a second look before you spend them. Identify any coin free with Change Finder; full values, grading and the error checker are Pro.
Try Change Finder free → check your coinsMint errors are where the big money hides. Photograph both sides of your coin and scan it — Change Finder checks for the known error types automatically.
48 coins to look for
25 Pence 'EXPERIMENTAL COIN 1981 / ROYAL MINT TRIAL' seven-sided trial piece£300–£68002015 First World War 'Royal Navy' £2 mule missing 'TWO POUNDS' denomination£300–£10001998-2008 (Beeston Collection example) 2p struck on a Five Pence (cupro-nickel) planchet — undersized silver 2p£100–£7202008 20p struck on a Five Pence planchet (undersized cupro-nickel)£75–£6002009 20p overstruck on an already-struck One Penny (double-denomination, ghost ONE PENNY lettering)£75–£12002002 1/10oz Gold Proof Britannia mule (Maklouf obverse on 2002 coin)£42–£701994 (dated); released 1998 1994 'ROYAL MINT TRIAL' bimetallic £2 pack (Mayflower reverse)£24.75–£902015 "Silver" 2p£814.2–£2171.22023-25 Bee single-metal 'all one colour' error£600–£16002016 trial piece£576–£18001971 'New Pence' 2p on a halfpenny blank£300–£8001985 2p on a wrong/foreign planchet£300–£8002007 Act of Union - WRONG EDGE (Newton legend)£300–£15002014 Lord Kitchener WWI - NO "TWO POUNDS"£300–£10002011 Aquatics "LINES OVER FACE"£180–£15002018-19 Paddington double strike£180–£480Dual-dated (2016 obv / 2017 micro-rev)£180–£3000Athletics 2009-DATED£150–£4002014 trial piece£141–£3761983 "NEW PENCE" 2p£120–£15002015 trial piece£120–£5002017+ Struck on a round blank£120–£320
2016 Shakespeare Tragedies WRONG EDGE£73.8–£196.82017 Sir Isaac Newton "lines on the Queen"£60–£1602015 Britannia INVERTED EFFIGY£60–£1602008 UNDATED 20p (mule)£30–£4002017 Benjamin Bunny ROTATION error£18–£2502016-17 Peter Rabbit 'lump under foot' / 'extra whisker'£15–£40various Missing edge inscription£15–£75
various Medal-alignment (die rotation)£9–£402009 Kew Gardens weak-strike pagoda£6–£301999 Rugby World Cup "999" edge£4.8–£200
2024 Gruffalo's Child 'three toes' (BU only)£3–£432022 KCIII Memorial 'no date'£1.2–£31971-73 1973 / 1971 large 10p struck in bronze2008-10 'Upside-down 1' rim die-break2008 50p struck on a 1p planchet2018 Paddington at the Palace 'crisp packet'2017+ Partial collar / half-round edge2023-25 Bee - raised metal on bee (die crack/chip)1994 Bank of England gold proof mule2005 clipped inner core2006/2014 2006 & 2014 £2/50p 'double denomination'
2010 Florence Nightingale on foreign blank2015 Royal Navy 'cat / flag on mast'various Inner core spilled / gap between metalsvarious Monometallic 'no inner core' (Holy Grail)1999 Princess Diana £5 crown - rotated die (~80 degrees clockwise)
2016 Shakespeare Tragedies WRONG EDGE£73.8–£196.82017 Sir Isaac Newton "lines on the Queen"£60–£1602015 Britannia INVERTED EFFIGY£60–£1602008 UNDATED 20p (mule)£30–£4002017 Benjamin Bunny ROTATION error£18–£2502016-17 Peter Rabbit 'lump under foot' / 'extra whisker'£15–£40various Missing edge inscription£15–£75various Medal-alignment (die rotation)£9–£402009 Kew Gardens weak-strike pagoda£6–£301999 Rugby World Cup "999" edge£4.8–£2002024 Gruffalo's Child 'three toes' (BU only)£3–£432022 KCIII Memorial 'no date'£1.2–£31971-73 1973 / 1971 large 10p struck in bronze2008-10 'Upside-down 1' rim die-break2008 50p struck on a 1p planchet2018 Paddington at the Palace 'crisp packet'2017+ Partial collar / half-round edge2023-25 Bee - raised metal on bee (die crack/chip)1994 Bank of England gold proof mule2005 clipped inner core2006/2014 2006 & 2014 £2/50p 'double denomination'2010 Florence Nightingale on foreign blank2015 Royal Navy 'cat / flag on mast'various Inner core spilled / gap between metalsvarious Monometallic 'no inner core' (Holy Grail)1999 Princess Diana £5 crown - rotated die (~80 degrees clockwise)Values are indicative collector ranges from public sources and depend on condition, grade and demand — not an offer, valuation or financial advice. Change Finder is independent and not affiliated with The Royal Mint.