Gold bar serial number check: what a serial number proves, how to verify it, and its limits

What is stamped on a gold bar, and why

The marks on a wholesale bar follow the refiner's own design, and for bars traded in the London market they follow the LBMA Good Delivery Rules. Those rules require every gold bar to carry the refiner's stamp, an assay mark, the fineness to four significant figures and a serial number of no more than 11 digits or characters. Bars made from January 2019 also carry the month and year of manufacture, as MMYY, either as a separate stamp or as the first four digits of the serial number. The characters for fineness, date and serial number must be at least 12 mm high, applied by pressure stamping or dot matrix; laser engraving is not permitted. Those rules cover the large London bar; kilobars and smaller bars follow each refiner's own design, so for them the refiner's published specification is the reference. The bar standards are set out on gold bar specifications and 1 kg gold bars.

What a serial number proves, and what it does not

A serial number is an index entry, not a security feature. It lets a refiner, a vault or an assayer look up what was recorded when the bar was made: the melt, the assay, the weight and the date. Inside a chain of custody that never breaks, from refiner to vault to buyer, the number works, because the bar and its record have never been apart. The LBMA describes the risk of a fraudulent Good Delivery bar entering the wholesale London market as extremely low, and that is the reason: the bars stay inside the chain.

Outside that chain the number is a claim like any other mark. In August 2019 Reuters reported, citing executives of the four largest Swiss refiners, that kilobars fraudulently stamped with those refiners' logos had been found in the vaults of a major bank and with other traders: at least 1,000 bars worth at least USD 50 million over the previous three years, by the executives' count. The bars were real, high-purity gold; the marks were false, and the bank had found two kilobars with the same identification number. Swiss customs had reported 655 forged bars to prosecutors in 2017 and 2018. A copied serial number from a genuine bar will pass a lookup, because the record it points to is real. The number therefore answers one question only: does the refiner have a record of this number? It never answers what the bar is made of, which is the question an assay answers. See gold assay.

The verification routes

What the producers' tools say about themselves. We describe these as their own pages describe them, on 2 November 2026, and endorse none. The Royal Canadian Mint's Bullion DNA covers Gold Maple Leaf coins dated 2014 and later and Silver Maple Leaf coins dated 2015 and later, not bars: an approved dealer places the coin in a device, photographs it through an application, and the Mint's server matches the image against the one captured at production. The Perth Mint's guidance on fakes points to its mintmark, a micro-engraved authentication feature on bullion coins, tamper-evident packaging on minted bars that shows the word VOID when opened, and exact weights and dimensions; it offers no verification service and says its bullion coins carry no certificate of authenticity. PAMP operates a verification application called VERISCAN; its product pages refused our request, so we do not describe it. Valcambi's site, as read, describes facility and transport security and no holder-facing verification service, and Argor-Heraeus's site could not be reached. The LBMA has accredited physical security features for bars since 2020, which it calls akin to a bar passport, but their adoption is at the discretion of the London vaults, and a bar outside that system carries none.

A worked checklist

1. Record the marks. Write down the refiner, fineness, serial number, date and any weight mark, and photograph every face in good light.
2. Compare with the refiner's published design. Format, dimensions, typeface and the position of each mark. A refiner's catalogue or weight list is the reference, not the seller's certificate.
3. Place the refiner. Check the LBMA and UAE Good Delivery lists. A refiner on neither list is not therefore fraudulent, but its bars will be re-assayed by any accredited buyer, and that cost belongs in the price.
4. Ask the refiner in writing. Send the marks and photographs and ask whether the number exists in its records and whether the details match. Keep the reply with its date.
5. Weigh and measure. Compare with the published specification on a precision scale and with callipers.
6. Test the whole bar. Precise density measurement or ultrasound, which look inside the bar. Methods are on the fake gold bars page.
7. Assay before you pay. Fire assay of a sample you saw taken, at a laboratory you chose, with an umpire named in the contract. This is the only step that proves the metal.
8. Reconcile the paper. Certificate of analysis, invoice, export permit and any certificate of origin must carry the same numbers, weights and fineness as the bar. Confirm each certificate with its issuer, never through the seller.
9. Keep the file. Each check, who did it and on what date, so that a compliance reviewer can follow how you decided. The order of checks for any purchase is on the five due-diligence checks.

Bars from Uganda

No Ugandan refinery was on the LBMA Good Delivery List for gold or on the UAE Good Delivery membership list when we read them on 2 November 2026. A bar refined in Uganda therefore carries the marks of a non-accredited refiner: its stamp, fineness and serial number are that refiner's own statements, with no accredited audit behind them and no entry in any Good Delivery weight list. Verification of such a bar rests on the metal, not on the stamp: weight, density and a fire assay on arrival, settled by an umpire if results differ, which is how accredited refiners treat bars from outside the lists. See gold refining in Uganda.

Uganda's Mining and Minerals Act 2022 adds two points a buyer should know. An export permit does not exempt the exporter from supplying a certificate of analysis authenticated by the country of origin (s.150(4)(c)), so a lawful consignment carries an assay document whose numbers should match the bars. And it is an offence to counterfeit, alter, obliterate or deface any stamp or mark, or to knowingly receive minerals acquired in contravention of the Act (s.256), and to falsify a certificate of origin (s.257(1)). Those provisions punish forgery after the event; they do not verify a bar for you. The export documents are explained on documents and compliance and the rules on Uganda gold regulations.

Warning signs

• A serial number that appears in more than one offer. The 2019 case turned on duplicated numbers. Search any number you are given, and treat a number seen on another seller's bar as a stop.
• Photographs of bars as proof of product. A photograph proves that a photograph exists. Bars in a picture can belong to anyone, and the marks in it can be copied onto anything.
• Certificates the issuer cannot confirm. A certificate of analysis, a refiner's certificate or a certificate of origin that the named issuer will not confirm directly to you is worth nothing, whatever the bar carries.
• An LBMA or Good Delivery description for a refiner not on the list. Check the list yourself on the day.
• A seller who controls the test. An XRF reading at the seller's office, or an assay from a laboratory the seller chose on a sample you did not see taken, is none of the routes above.
• A price well below the benchmark. A bar is priced from its fine weight and the gold price; a deep discount is a reason to stop, not a bargain. See how to check a Ugandan gold supplier.

Where Uganda Gold Report stands

Uganda Gold Report is developing documented gold-sourcing routes and welcomes enquiries from qualified international buyers. Product availability, specifications, seller authority and export eligibility are subject to independent verification and applicable regulatory approvals.

We hold no bars, no stock and no Ugandan licence, and we have never issued a serial number, certificate or assay. We publish this page so that a buyer can test any bar offered, including any bar we may one day offer, by the same routes. If you have a genuine requirement, send us your form, fineness, quantity and destination and we will reply with what can and cannot be quoted at this stage. See also how buying gold from Uganda works.