THE SHORT ANSWER
The London standard is a variable-weight wholesale bar, not every branded gold bar
An LBMA Good Delivery gold bar contains 350 to 430 fine troy ounces, has minimum fineness of 995.0 and must meet marking, dimensional and appearance rules. A one-ounce minted bar or kilobar is not itself a London Good Delivery bar just because its manufacturer appears on the Good Delivery List.
Not one fixed 400 oz.
Wholesale acceptance floor.
Exact bars vary.
Date applies to newer production.
CURRENT SPECIFICATION
Preserve ranges and qualifiers exactly
| Field | Current rule | Interpretation |
|---|---|---|
| Fine gold | 350-430 troy oz | Fine-content range, not a gross-weight promise |
| Fineness | 995.0 minimum | Parts per thousand |
| Top length | 250 +/- 40 mm | Permitted range |
| Top width | 70 +/- 15 mm | Permitted range |
| Height | 35 +/- 10 mm | Permitted range |
The standard also governs appearance, safe handling and weight-list procedures. A dimension inside a range is not an online authenticity verdict, and a retail bar should not be forced into these institutional dimensions.
KILOBAR BOUNDARY
Listed refiner does not turn a kilobar into a Good Delivery bar
LBMA's market guide directly answers this common confusion: kilobars do not meet the London Good Delivery gold-bar criteria. LBMA also describes a separate 999.9 kilobar specification developed with the Shanghai Gold Exchange. Keep the manufacturer, product standard and bar itself as three separate claims.
Check current or former official listing.
Match official record and date.
Issuer page or certificate.
Needs converging evidence or assay.
MARKING RULE
New wholesale bars carry a durable identity chain
Current rules call for refiner stamp, assay mark, fineness and a serial number of no more than 11 characters. For production from January 2019, month and year must also appear. Pressure stamping and dot matrix are permitted; laser engraving is not. Mark characters must be at least 12 mm high.
The 10 mm edge-clearance rule applies from January 1, 2026 to new bar changes and Good Delivery List applicants. It should not be projected backward onto every existing bar or refinery. Historical bars always require the rule version and mark in effect for their production era.
PRIMARY SOURCES
Rules, issuer records and consumer safeguards
- LBMA Good Delivery technical specifications for wholesale-bar weight, fineness, marks, date and dimensional fields.
- LBMA Gold Current List for a dated refiner and current-bar-mark check. GoldObserve links to the list rather than reproducing its proprietary contents.
- LBMA proactive monitoring procedures for continuing assay capability and quality-assurance context.
- Royal Mint serialized packaging FAQ for one issuer's matching-serial and opened-package boundary.
Reviewed August 12, 2026. List status, bar marks, packaging and product specifications can change; record the exact source and check date.
FAQ
Good Delivery gold-bar questions
How much does an LBMA Good Delivery gold bar weigh?
The current standard is defined by 350 to 430 fine troy ounces, roughly 10.9 to 13.4 kilograms of fine gold. A 400-ounce description is an approximation, not one exact weight.
Is a one-kilogram gold bar an LBMA Good Delivery bar?
No. LBMA explicitly distinguishes kilobars from the London Good Delivery gold-bar specification, although a listed refiner may manufacture both.
What is the minimum fineness?
The current Good Delivery gold specification requires at least 995.0 parts per thousand fine gold.
Does an LBMA-listed refiner make every retail bar authentic?
No. Refiner status and an official bar mark are useful source evidence, but a retail item still requires provenance, specification checks and suitable testing when evidence conflicts.