How can I tell if a gold sovereign is fake?

Six tests, in order of speed and reliability. (1) Weight: 7.988 g ± 0.020 g. Use a precision digital scale to 0.01 g resolution. Off-weight by > 0.05 g = fake. (2) Diameter: 22.05 mm ± 0.05 mm. Use a digital calliper. (3) Magnet test: 22-carat gold is non-magnetic. Any magnetic pull = plated steel. (4) Edge inspection: milled (reeded), uniform, no horizontal seam. Cast counterfeits show a faint horizontal seam where the two mould halves joined. (5) Specific gravity test: 22-carat gold density = 17.7 g/cm³ via water displacement. The definitive non-destructive authentication test for tungsten-core fakes. (6) Sound test: a genuine sovereign rings with a high-pitched clear tone when balanced on a fingertip and tapped; counterfeits sound dull. For coins worth £500+, professional grading by PCGS, NGC or CGS UK is essential.

What types of fake sovereigns exist?

Five categories. (1) Plated brass / steel: cheapest fakes; fail magnet, weight and diameter. Common on eBay at suspiciously low prices. (2) Cast 22-carat gold: technically the right gold content but not struck by Royal Mint dies. Detect by horizontal mould seam on the edge. Match weight and density tests. Often passable visually. (3) Modern struck counterfeits with correct gold content: hardest to detect; require magnification of design details (Pistrucci's St George dragon detail, Queen's portrait sharpness, edge milling pitch). (4) Tungsten-core gold-plated: tungsten matches gold density (17.7 vs 19.3 for pure gold) very closely; defeats the specific-gravity test. Detect by ultrasonic thickness probing or precise sound test. Mainly an issue with gold bars/large coins; relatively rare on sovereigns. (5) Date-altered genuine sovereigns: real sovereigns with the date re-engraved (e.g. 1908 turned into 1908 C). Detect by tooling marks under 10x magnification.

Can I trust eBay sovereign listings?

Mixed. BNTA-member dealer listings on eBay UK are generally trustworthy — the British Numismatic Trade Association requires authentication standards from members. Slabbed PCGS / NGC / CGS UK examples are authenticated by the grading service and very safe. Raw private-seller listings under £400 are higher risk. Bullion-dealer listings (BullionByPost, Atkinsons via eBay) are safer because their reputation is at stake. Two specific red flags: prices significantly below current bullion floor (£425 at £1,750/oz spot) suggest a fake or stolen coin; sellers with limited feedback history and high-value sovereigns are higher risk. Always cross-check sold-listings prices and ask for additional photographs of the edge before any high-value purchase.

Are modern Royal Mint sovereigns also faked?

Yes, but less than rare-date Victorian and Edwardian sovereigns. The numismatic premium on modern sovereigns is small (5-7%) so the economic incentive for forgers is lower than for, say, an 1879 Sydney shield-back at 5-10x bullion value. That said, fakes of modern Elizabeth II and Charles III sovereigns do appear on eBay, particularly tungsten-core specimens that test correctly on simple weight checks. The safest path for buying modern sovereigns is direct from the Royal Mint or from a Royal Mint-authorised dealer with a buy-back guarantee. For older modern sovereigns (e.g. 1989 500th anniversary), professional grading is recommended.

How do I do a specific-gravity test at home?

Need a precision digital scale (0.01 g resolution), a small container of water, and a thin string or fine wire. (1) Weigh the coin dry on the scale: record as W_dry. (2) Suspend the coin from the scale on the wire so it's submerged in water but not touching the container walls or bottom. Record the new reading: W_wet. (3) Calculate density: density = W_dry / (W_dry - W_wet). For a genuine 22-carat sovereign, density should be 17.65 – 17.78 g/cm³. Pure gold is 19.32 g/cm³; tungsten is 19.25 g/cm³; lead is 11.34; brass 8.4-8.7; steel 7.85. The 17.7 reading rules out everything except 22-carat gold or tungsten-22-carat-gold composites. For high-value coins, professional non-destructive XRF testing at a reputable jeweller or the Royal Mint costs £15-30 and is definitive.

What about counterfeit Sovereign mint marks?

Specific concern. The S/M/P/SA/I/C branch mint marks are valuable in their own right (Sydney sovereigns trade at 5-15% premium over London, Bombay at 200-400%, Ottawa at variable but often huge premium for key dates). Counterfeiters add fake mint marks to genuine no-mintmark London sovereigns to achieve the higher branch-mint price. Detect by examining the mint-mark area under 10x magnification: a genuine struck mint mark sits in the same relief plane as the surrounding design; an added mint mark shows tooling marks, slightly different relief depth, and often a visible disruption to the surrounding metal flow. For any sovereign claimed to be a key-date branch-mint piece (1908 C Ottawa, 1918 I Bombay, 1879 S Sydney, etc.), professional grading by PCGS or NGC is essential. See our sovereign mint marks UK guide.

What should I do if I think I have a fake sovereign?

Three options. (1) BNTA-member dealer second opinion: most reputable UK coin dealers will examine a coin in person and give a verbal authentication for free or a small fee (£5-15). Their reputation depends on accurate calls. (2) Submit to a third-party grading service: PCGS, NGC or CGS UK will authenticate AND grade in one step for £25-50 per coin. They reject confirmed fakes (which provides definitive evidence). (3) XRF testing: some Royal Mint-authorised dealers offer non-destructive X-ray fluorescence testing for £15-30, which conclusively identifies the metal composition. If you bought the coin from a UK seller and it's confirmed fake, you have legal recourse under the Sale of Goods Act — demand a full refund. eBay UK Buyer Protection covers most cases for up to 6 months from purchase.

Are Krugerrand fakes also a concern?

Yes — arguably more than sovereigns. The 1 oz Krugerrand has been the most-counterfeited gold coin globally because of its high recognition and reasonable price point. Krugerrands are not UK legal tender so they fall outside the CGT exemption that applies to sovereigns and Britannias — this is a separate concern. UK collectors who hold Krugerrands face CGT on any future gain plus the same authentication risks as sovereigns. For UK-resident gold-coin investors, the materially better choice is UK legal-tender bullion (sovereigns, Britannias, Queen's Beasts, Tudor Beasts) which combine the CGT advantage with the same authentication infrastructure. See our sovereigns vs Britannias guide.

How can I authenticate before buying?

Three layers. Pre-purchase: ask for additional photos — clear obverse, clear reverse, edge close-up showing milling. Compare against verified images on PCGS CoinFacts and Numista. At purchase: for in-person purchases, weigh on a precision scale, measure with a calliper, examine edge under 10x magnification, do a magnet test. Post-purchase: for any high-value sovereign (£500+), submit to PCGS, NGC or CGS UK for grading and authentication within the return window. Most UK coin dealers offer a 14-day return window under distance-selling regulations; eBay UK extends Buyer Protection to 30 days. Use the window if you have any doubts.

What is a "filler" sovereign and is it a fake?

A "filler" or "filler-grade" sovereign is a genuine sovereign that has been damaged, holed, scratched, mounted in jewellery, or otherwise impaired. It is NOT a counterfeit — it is a real Royal Mint sovereign that someone modified. Filler sovereigns trade at gold-content value (£425 at £1,750/oz spot) plus a small premium because they retain the gold but have lost numismatic value. For investors who want gold exposure and don't care about numismatic premium, fillers are economical — you get the gold at near-melt without paying the 5-30% numismatic premium of clean specimens. The legal status as UK legal tender is unchanged so CGT exemption still applies.

How to Spot a Fake Gold Sovereign: Six Authentication Tests

The gold sovereign is the most-counterfeited British gold coin because of its high recognition and reasonable price point. Fakes range from cheap plated brass that fails a magnet test to sophisticated tungsten-core counterfeits that pass weight and diameter checks. This guide covers the six authentication tests every sovereign buyer should know, the five categories of fake to recognise, and where to get professional authentication when the stakes warrant it.

Last updated: 6 May 2026

In brief. Genuine sovereign: 7.988 g, 22.05 mm, non-magnetic, milled edge, density 17.7 g/cm³. Five fake categories: plated brass / steel, cast 22-carat, modern struck counterfeits, tungsten-core gold-plated, date-altered. Six tests cover them all. Professional grading by PCGS / NGC / CGS UK (£25-50 per coin) is the gold-standard authentication for coins worth £500+.

Sovereign specifications — what genuine looks like

Property	Genuine sovereign
Weight	7.988 g ± 0.020 g
Diameter	22.05 mm ± 0.05 mm
Thickness	1.52 mm
Composition	22-carat gold (.9167) + copper alloy
Pure gold content	7.32 g (0.2354 troy oz)
Specific gravity (density)	17.65-17.78 g/cm³
Magnetic?	No (gold and copper are non-magnetic)
Edge	Milled (reeded), seam-free, uniform pitch

Featured sovereigns on MyCoinage

½ Sovereign - Elizabeth II 3rd portrait; Proof

1985

up to £7,155

1 Sovereign - Elizabeth II Gold Sovereign Anniversary

1989

up to £1,588

1 Sovereign - Elizabeth II 4th portrait; Golden Jubilee

2002

up to £1,395

1 Sovereign - Charles III Bullion

2026

up to £1,300

1 Sovereign - Elizabeth II 5th portrait; Platinum Jubilee

2022

up to £1,128

1 Sovereign - Charles III

2026

up to £1,057

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Reviewed by Connor Jones, Editor. Every MyCoinage guide is fact-checked against realised auction sales before publication.

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