Reference

Brilliant Uncirculated vs Uncirculated vs Proof: The Royal Mint Grade System

“BU” sits on every Royal Mint commemorative pack. “UNC” appears in dealer descriptions. “Proof” commands £30+ above face value. “Specimen” and “Piedfort” occasionally surface on auction lots. Understanding which is which is the difference between paying £5 above face value and £500. This reference walks through every Royal Mint and slabbing-firm grade designation, the finishes behind them, and the realistic premium each commands.

Last updated: 22 June 2026
In brief. UNC means a coin that’s never circulated. BU is a Royal Mint product label for a specially-struck UNC coin. Proof is a separately-struck mirror-finish coin. Specimen sits between BU and Proof. FDC (Fleur-de-Coin) is the “flawless” designation. PCGS / NGC use MS-60 to MS-70 to grade all of them on a single 70-point Sheldon scale.

The five non-circulated finishes

Once a coin leaves the Royal Mint without entering circulation, it can fall into one of five distinct finish categories. They’re not strictly “grades” in the Sheldon sense (which measures wear) but rather finish types defined by the striking process. Each commands its own premium tier:

FinishStriking methodTypical mintagePremium over face
Uncirculated (UNC)Standard die, single strikeMass productionFace to +20%
Brilliant Uncirculated (BU)Polished die, single strike, special blank50k–1m+£5 to +£15
SpecimenPolished die, single strike, special blank in presentation set5k–50k+£15 to +£40
ProofHighly polished die, double or triple strike, polished blank3k–20k+£30 to +£100
Piedfort ProofProof method on double-thickness blank1k–5k+£100 to +£500

The five finishes form a quality ladder. Each rung up the ladder requires more die preparation, more strikes per coin, more controlled handling and a smaller print run — which is why the premium per coin grows so steeply.

What “Uncirculated” technically means

An uncirculated coin has never been used in commerce. It carries no wear from handling transactions, retains its original mint lustre, and shows only the contact marks acquired in the Royal Mint’s own bagging and shipping process. On the Sheldon scale UNC covers grades MS-60 to MS-70:

  • MS-60 / MS-61. No wear, but heavily bag-marked. The lowest acceptable UNC.
  • MS-62 / MS-63. Scattered bag marks; full lustre. “Choice BU.”
  • MS-64 / MS-65. Minor marks only, attractive eye appeal. “Gem BU.”
  • MS-66 / MS-67. Very minor marks, exceptional lustre. “Premium Gem.”
  • MS-68 / MS-69. Near-perfect, minimal imperfection visible only under magnification.
  • MS-70. Flawless under 5× magnification. “Perfect.”

The crucial point: every coin from MS-60 through MS-70 is uncirculated. The differences within the band are surface quality, not wear. A coin with so much as a hint of friction on the highest design point drops to AU-58 or lower, no matter how lustrous the rest of the surface looks.

What “Brilliant Uncirculated” adds — the Royal Mint product

The “Brilliant Uncirculated” designation is a Royal Mint trademark for a specific commemorative product line. Every BU coin is uncirculated, but not every uncirculated coin is BU. Three production differences separate a Royal Mint BU coin from a circulating uncirculated coin of the same year:

  1. Polished dies. The dies used to strike BU coins are hand-polished to a higher mirror finish than circulating dies. Field areas of the resulting coins are noticeably brighter and reflect light more cleanly.
  2. Specially-prepared blanks. The blank coin discs (planchets) used for BU strikes are burnished and inspected before striking, removing the small bag marks that come with mass-produced circulating blanks.
  3. Capsule packaging. Each BU coin is sealed in an air-tight plastic capsule directly after striking, then mounted in a presentation card or folder. The coin never touches another coin, never enters a bag, and never sees a hand without gloves.

The result is typically a Sheldon MS-65 to MS-67 strike, with strong eye appeal, sharp design detail, and immaculate fields. BU packs are sold at £5–£15 above face value depending on denomination and mintage; secondary market values for low-mintage BU packs (under 100,000) often run £30–£200+.

Proof vs BU vs Specimen vs Piedfort

The clearest way to distinguish the four Royal Mint finishes is by the visual and tactile features of each:

FeatureUNC (circulating)BUSpecimenProofPiedfort Proof
Field finishLustrousBright lustrousStrong lustreMirrorMirror
Device finishLustrousLustrousLustrousFrostedFrosted
Strike count1112–32–3
Blank prepStandardBurnishedBurnishedPolishedPolished, double thickness
CapsuleNoYesYesYesYes
Typical retailFace valueFace + £5–15+£15–40+£30–100+£100–500

The single biggest visual difference: a proof coin has cameo contrast — a deep mirror in the field area against frosted devices (the bust, design and lettering). A BU coin lacks this contrast; both field and device are lustrous but neither is mirror or frosted. Place a 2022 Britannia BU £2 next to a 2022 Britannia Silver Proof £2 under raking light and the difference is immediately obvious.

Royal Mint pack types: BU, Proof and Specimen

The Royal Mint sells commemorative coins through several distinct pack formats. Each maps onto one of the finish types above:

  • Brilliant Uncirculated pack. Single coin in a capsule, mounted on a presentation card with a certificate of authenticity. Retail £10–£25. Mintages 50k–500k. The standard commemorative product.
  • Annual proof set. The full year’s circulating denominations plus commemoratives in proof finish, in a presentation box with certificate. Retail £100–£200. Mintages 3,000–15,000 typically.
  • Silver proof. Single coin in sterling silver, struck to proof finish. Retail £60–£100 for a 50p; £100–£200 for a £2. Mintages 2k–10k.
  • Gold proof. Single coin in 22-carat gold, proof finish. Retail £800–£3,000 depending on weight. Mintages 250–1,500.
  • Piedfort silver proof. Sterling silver double-thickness blank, proof finish. Retail £120–£250. Mintages 1,000–3,500.
  • Specimen set. Rare modern usage; a presentation set struck to a finish above BU but below proof, sold for milestone events (1972 silver wedding, 1981 royal wedding).

For a deeper review of Royal Mint subscription products, see our Royal Mint subscription review.

When the BU label commands a real premium

Three factors drive the secondary-market value of a Royal Mint BU pack:

  1. Mintage. Below 100,000 packs, BU premium is usually meaningful. Above 1 million packs, the BU label is mostly marketing — the coin trades at face value or slightly above. The Kew Gardens 50p BU pack (mintage 210,000) trades at £180+; the 2012 Olympic 50p BU pack (mintage 1.4 million across the series) trades at £5–£10 each.
  2. Theme strength. Cross-over collector interest pushes prices regardless of mintage. Beatrix Potter, Harry Potter, Paddington and Olympic series carry premium because they attract buyers from outside numismatics. See Peter Rabbit 50p, Harry Potter 50p and Paddington 50p.
  3. Sealed condition. An opened BU pack loses 30–50% of premium versus a sealed pack, because the seal is the authentication. Once opened, the coin must be authenticated independently (PCGS / NGC slab) to recover liquidity at the BU price.

The BU premium is real for low-mintage coins; the BU premium is minimal or zero for mass-issue coins. Always check our database for the actual realised auction prices before assuming a BU pack is “worth” the Royal Mint asking price.

Spotting a damaged BU coin vs a genuine BU coin

Once a BU pack is opened the coin can be damaged in seconds. Five tells will identify a degraded BU coin masquerading as fresh:

  • Lustre breaks. Tilt the coin under raking light. The cartwheel reflection should be unbroken across the entire field. A break indicates either wear (the coin has touched cloth or skin) or cleaning damage.
  • Hairlines. Under 10× magnification, look for thin parallel scratches on the field. Hairlines come from cleaning with a cloth, jewellery polish, or any abrasive contact. They are irreversible and cap the grade at “Details, Cleaned.”
  • Fingerprints. Faint oval marks where skin oils have toned the surface. Common on opened BU packs handled without gloves. Light prints can sometimes be reduced by professional restoration; heavy prints are permanent.
  • Tone ring. A circular discoloration where the capsule edge has trapped moisture. Indicates the pack has been stored in a humid environment.
  • Edge marks. Reeded edges should be sharp and unblemished. A flat spot or ding on the rim signals the coin has been dropped onto a hard surface.

PCGS / NGC / CGS UK mapping for BU and UNC

All three major slabbing services use a 1–70 numeric scale (CGS UK uses 1–100). Here’s how Royal Mint descriptive grades map to slabbed numeric grades:

Royal Mint labelPCGS / NGC (Sheldon)CGS UK (1–100)Description
UNC (basic)MS-60 to MS-62UNC-78 to UNC-82Uncirculated, scattered bag marks
BU pack standardMS-63 to MS-65UNC-82 to UNC-88Choice / Gem BU
BU pack premiumMS-66 to MS-67UNC-88 to UNC-92Premium Gem BU
Specimen / top BUMS-68UNC-92 to UNC-94Near-perfect, sharp strike
Proof standardPR-65 to PR-68PR-88 to PR-94Mirror with cameo
Proof premiumPR-69 DCAMPR-94 to PR-96Deep cameo, near-flawless
FDC / Perfect ProofPR-70 DCAMPR-98 to PR-100Flawless under 5×

For a full breakdown of which grading service to choose, see our PCGS vs NGC vs CGS UK comparison. For when slabbing makes economic sense, see should I grade my coins UK.

½ Sovereign - Elizabeth II 3rd portrait; Proof
½ Sovereign - Elizabeth II 3rd portrait; Proof
1985
up to £7,155
5 Pounds - Elizabeth II Royal Wedding; Gold Proof
5 Pounds - Elizabeth II Royal Wedding; Gold Proof
2011
up to £4,687
5 Pounds - Elizabeth II Una and The Lion; Silver Proof
5 Pounds - Elizabeth II Una and The Lion; Silver Proof
2019
up to £1,930
2 Pounds - Elizabeth II 75th VE Day; Gold Proof
2 Pounds - Elizabeth II 75th VE Day; Gold Proof
2020
up to £1,761
1 Sovereign - Charles III Life of Queen Victoria; Gold Proof
1 Sovereign - Charles III Life of Queen Victoria; Gold Proof
2026
up to £925
5 Pounds - Elizabeth II Gothic Crown Quartered Arms; Silver Proof
5 Pounds - Elizabeth II Gothic Crown Quartered Arms; Silver Proof
2021
up to £925

Frequently asked questions

What is the difference between BU and UNC?
“Uncirculated” (UNC) is a technical condition: a coin that has never entered circulation and retains full original mint lustre. “Brilliant Uncirculated” (BU) is a Royal Mint product designation: a specially-prepared striking with mirror-like fields and frosted devices, sold in capsules or presentation packs at a premium over face value. On the Sheldon scale all UNC and BU coins fall into the MS-60 to MS-70 range, but BU coins are typically MS-65 or higher because of the special striking process. In the secondary market a Royal Mint BU pack commands roughly a 10–30% premium over a circulation-strike UNC coin of the same year.
Is BU the same thing as proof?
No. A proof coin is struck two or three times from highly polished dies onto specially-prepared blanks, producing the deepest mirror fields and the sharpest frosted relief possible. A BU coin is struck once from polished dies onto regular blanks — it has full lustre and excellent surfaces but lacks the multi-strike depth of a proof. Visually, a proof shows a deep cameo contrast and edge-to-edge mirror; a BU shows strong lustre but no mirror finish. Royal Mint BU packs sell at £5–£15 above face value; proofs at £30–£100+. See our proof coin guide.
What does “Mint State” mean?
Mint State (MS) is the US grading term for any uncirculated coin, covering Sheldon grades 60 through 70. PCGS and NGC slabs always use MS for uncirculated business-strike coins (MS-60 to MS-70). Royal Mint commemorative packaging uses BU. The two systems describe the same condition tier; MS-60 is roughly equivalent to a heavily bag-marked UNC, MS-65 maps to a typical Royal Mint BU pack, and MS-70 maps to FDC (Fleur-de-Coin). Our grading guide has the full Sheldon-to-UK mapping.
Should I keep a coin in its Royal Mint BU pack?
For resale value, yes. A coin still sealed in its original Royal Mint BU pack typically trades at 10–25% above the same coin loose. The pack itself provides authentication, protection from handling and toning, and the certificate of authenticity that buyers expect. Once the seal is broken the pack still has value as a presentation case, but the “sealed BU pack” premium evaporates. The exception: if you intend to send the coin to PCGS or NGC for grading, the pack will be opened during submission — the slab then takes over as the authentication container.
Can a BU coin be damaged?
Yes, easily. BU coins are still subject to handling marks, fingerprints, hairline scratches from cloth wiping, and toning from acidic environments. A Royal Mint BU coin removed from its capsule and dropped onto a hard surface drops to MS-62 or lower. Worse, attempting to clean a tarnished BU coin with metal polish or any abrasive removes the mint lustre permanently and drops the grade to a “Details” designation that caps resale at 30–70% below straight-grade peers. The rule: if you have a sealed BU pack, leave it sealed.
What does PCGS / NGC call a Brilliant Uncirculated coin?
On the Sheldon scale, a Royal Mint BU coin will typically grade MS-65 to MS-67 when submitted to PCGS or NGC. Some exceptional examples reach MS-68 or MS-69; MS-70 is reserved for genuinely flawless coins under 5× magnification. CGS UK uses an equivalent 1–100 scale where BU maps to roughly UNC-78 to UNC-82, with the highest CGS grades (UNC-90+) corresponding to MS-69/70. The PCGS, NGC and CGS UK grading services all charge £20–£40 per coin for standard authentication.
Is “BU” on a slab the same as “BU” on a Royal Mint pack?
No. The two terms come from different grading traditions. Royal Mint “Brilliant Uncirculated” is a product description for a specially-struck commemorative coin sold above face value. Slabbed “BU” — rarely used by PCGS or NGC, more common on raw-coin dealer slabs — is a vague descriptor meaning “uncirculated, decent quality.” A PCGS or NGC slab will give a numeric MS-XX grade rather than the BU label. Treat “BU” on a non-graded coin as a marketing claim, not a guaranteed condition.
When does a BU pack actually trade above face value?
Three conditions need to be met for a Royal Mint BU pack to command a meaningful secondary-market premium: (1) low mintage — under 100,000 packs typically holds value, over 1 million does not; (2) strong design or theme — Beatrix Potter, Harry Potter, Olympic 50p packs hold premium because of crossover collector interest; (3) sealed condition — opened packs lose 30–50% of premium. A Royal Mint BU 50p with mintage 5 million carries no premium; a Kew Gardens 50p BU pack (mintage 210,000) trades at £180–£250 today.
What is “Specimen” finish?
A Specimen is a Royal Mint product midway between BU and proof: struck from polished dies but only once (not twice as a proof), onto a specially-prepared blank. Specimen sets — offered for the 1972 silver wedding crown, the 1981 royal wedding crown, and certain proof Olympic series — have stronger lustre than BU but lack the mirror finish of proofs. Specimens are increasingly rare in the modern Royal Mint catalogue; most issues are now BU or proof with no middle tier.
What is “Piedfort”?
A Piedfort (from French pied-fort, “heavy foot”) is a coin struck on a thicker-than-normal blank, typically twice the standard weight. Royal Mint Piedfort issues are always proofs, struck in sterling silver or gold from polished dies. They’re sold at significantly higher premium than standard proofs because of the doubled metal content and limited mintages. A 2012 Diamond Jubilee Piedfort £5 in silver retailed at £120; today it trades at £180–£220. Piedforts represent the apex of the Royal Mint commemorative range.
How can I tell a damaged BU coin from a genuine BU coin?
Five tells separate a true BU coin from a circulated coin marketed as BU: (1) full lustre — tilt under raking light, the “cartwheel” reflection should be unbroken; (2) no wear on high points — cheek, hair curls, eagle breast or shield points should be sharp; (3) no contact marks on focal areas — bag marks scattered away from the portrait are acceptable, marks on the face are not; (4) no hairlines under 10× magnification (hairlines indicate cleaning); (5) no toning rings from handling. A genuine MS-65+ BU coin satisfies all five; one or more failed tests drops the grade to AU or below.
Should I crack open a Royal Mint BU pack to grade it?
Only if the coin inside is likely to grade MS-68 or higher. Standard Royal Mint BU coins typically grade MS-65 to MS-67, where the cost of grading (£20–£40) and lost pack premium often exceeds the slab uplift. Specific exceptions: a low-mintage BU pack (under 50,000) where MS-69 or MS-70 examples sell for many times the BU price, or a BU coin you suspect has unusually clean fields and could be in the top 1% of the print run. For most collectors, the answer is leave the pack sealed.
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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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