What Sheffield Assay Office does

Sheffield Assay Office is one of four UK statutory Assay Offices, established by Act of Parliament in 1773 to assay and hallmark precious metal articles. Its core offering is hallmarking of gold, silver, platinum, and palladium under the Hallmarking Act 1973, using traditional punch methods and, since 1997, laser marking technology capable of handling hollow, semi-finished, and intricate jewellery. Beyond hallmarking, the Office operates a UKAS-accredited analytical laboratory (continuous accreditation since 1982, ISO/IEC 17025:2017) offering precious metal analysis, mercury screening, nickel-free and environmental testing, and a Diamond Verification Service that distinguishes natural from lab-grown diamonds. The facility at Hillsborough, Sheffield (purpose-built 2008) houses both the assay floor and analytical laboratories, plus an archive library of 4,000+ books dating to 1773.

The business operates on a transaction-based fee model: hallmarking charges per article or by weight, with premium expedited tiers (Early Hall at 100% surcharge, One Hour Service at a £70 minimum). Sponsor's mark registration runs £100 + VAT for a 10-year term (renewal £50 + VAT), and punch creation costs approximately £80-£95 + VAT. Distribution combines a walk-in customer counter in Sheffield, a daily courier collection service from Birmingham, London, Leicester, and Manchester, and nationwide postal/courier channels. The Office also publishes industry reference works, most notably Bradbury's Book of Hallmarks, which serves as the primary reference for English, Scottish, Irish and Convention hallmarks.

Customers span SMB jewellers and silversmiths (many with 20-40+ year relationships), high-street jewellery retailers, luxury brands including Bulgari, De Beers and Georg Jensen, healthcare/medical device companies (e.g., B Braun Hospicare), and individual craftspeople. The Office is governed by 30 Guardians under the 1773 Act and is the only UK Assay Office certified by the Responsible Jewellery Council. Leadership is anchored by Assay Master Ashley Carson, the longest-serving Assay Master in the Office's history, with 48 years of service as of 2025.

Name

Sheffield Assay Office

Legal name

Sheffield Assay Office

Website

https://assayoffice.co.uk

Company type

Private

Founded year

1773

Operating status

Operating

Headcount range

51–100 employees

Short description

Sheffield Assay Office, established by Act of Parliament in 1773, is one of four UK statutory Assay Offices providing hallmarking, UKAS-accredited analytical testing, and diamond verification services to jewellers, silversmiths, retailers, and healthcare companies.

Ownership category

akta.pro rank

Product category

Precious Metal Assay and Hallmarking Services

NAICS

Testing Laboratories and Services (541380)

SIC

Services-Testing Laboratories (8734)

akta.pro primary industry

Precious Metals Assaying, Metallurgical Testing & Certification (IMAKAEAK)

akta.pro secondary industries

Appraisal, Authentication & Insurance Documentation (CRAKALAH), Diamond Grading & Certification Laboratories (CRAKAJAG), Traceability, Provenance & Compliance Services (e.g., origin, AML/KYC, sanctions) (CRAKAJAL)

Keywords

• Precious metal hallmarking
• Analytical testing services
• Diamond verification
• UK assay office
• Jewellery authentication

Headquarters

HQ city

Sheffield

HQ country

United Kingdom

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Hallmarking Services: Primary revenue stream from assaying and hallmarking precious metal articles (gold, silver, platinum, palladium). Fees are charged per article or based on weight, with standard turnaround and premium services (Early Hall, One Hour Service). Revenue model is transaction-based, with clients invoiced upon completion of each consignment.
2. Analytical Services: UKAS-accredited testing services including metal and mineral analysis, mercury screening, environmental testing, nickel-free testing, and precious metal analysis for clients ranging from high street jewellery retailers to international healthcare companies.
3. Diamond Verification Services (DVS): Specialist service for authenticating natural diamonds and identifying lab-grown/synthetic diamonds for retailers and consumers.
4. Publications and Books: Sale of publications including Bradbury's Book of Hallmarks (hardback £25, paperback £15), History of the Assay Office (£4), Sheffield Assay Office Register (£10), Old Silver Platers and their Marks (£5).
5. Laser Marking Services: Custom laser engraving services for logos, signatures, serial numbers for decorative, promotional or engineering purposes. Cost-effective for one-offs and prototypes.

Pricing tiers

Go-to-market motion3 records

Distribution channels3 records

Marketing channels6 records

Core offering

Sheffield Assay Office provides statutory hallmarking of precious metals (gold, silver, platinum, palladium) under the UK Hallmarking Act 1973, UKAS-accredited analytical testing services for metals and minerals, and Diamond Verification Services (DVS) for authenticating natural versus lab-grown diamonds. It is one of only four UK assay offices with statutory authority to hallmark precious metal articles.

Product overview

Sheffield Assay Office offers a unified suite of services centered on hallmarking and precious metals authentication. The core offering includes hallmarking services (the primary service since 1773), analytical/laboratory testing services (UKAS accredited), and Diamond Verification Services (DVS) for identifying natural versus lab-grown diamonds. The portfolio also includes private assays for mark identification, daily collection services, and publications including Bradbury's Book of Hallmarks. All services are delivered from a single facility in Sheffield, UK.

Differentiator

Problem solved

Functional benefit

Brands

• Diamond Verification Services (DVS): Diamond Verification Services (DVS) - specialist service that accurately identifies the presence of natural or lab-grown/synthetic diamonds

Products and services

• Hallmarking Services Statutory hallmarking service for precious metals (silver, gold, platinum, palladium) under the UK Hallmarking Act 1973, including UK hallmarks, convention marks, laser marking, mixed metal marking, sponsor mark registration, and expedited same-day or one-hour services. Used by jewellers, silversmiths, manufacturers, and retailers across the UK.
• Analytical Services

Quantifiable outcome

• 40 years continuous UKAS accreditation
• +2 more outcomes

Named customers15 records

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Eight partnerships are on record, tiered core and minor.

• Goldsmiths NorthcoreGTM or Marketing Partner · 10 June 2026Annual contemporary jewellery and silverware fair held at Cutlers' Hall, Sheffield. Sheffield Assay Office representatives are present throughout the event, meeting exhibitors and visitors, discussing hallmarking services and offering advice on precious metals. The event showcases British craftsmanship and supports the jewellery and silversmithing community.
• Responsible Jewellery Council (RJC)coreOthersSheffield Assay Office is a certified member of the Responsible Jewellery Council, the world's leading standard-setting organization for the jewellery and watch industry. It is the only UK Assay Office to hold this certification. RJC accreditation covers core responsible business practices including regulatory compliance, responsible supply chains, human rights, labour rights, health and safety, environmental performance, product disclosure, and responsible mining.
• Sheffield Hallam UniversitycoreStrategic or Co-development PartnerLong-standing relationship with Sheffield Hallam University's BA Jewellery, Materials and Design degree programme. Sheffield Assay Office has sponsored precious metal materials for final-year degree show projects, enabling students to work in precious metals. Free registration and hallmarking services provided to students. The Assay Master annually judged and presented prizes at the final degree show. (Note: programme closing June 2026)
• Yorkshire ArtspaceminorStrategic or Co-development PartnerSheffield Assay Office supports the Starter Studio Programme at Yorkshire Artspace, providing sponsorship for young silversmiths and emerging designers in the jewellery and metalwork industry.
• British Hallmarking CouncilcoreOthersOfficial regulatory body overseeing UK hallmarking. The British Hallmarking Council sets standards for the Hallmarking Act and dealer notices. Sheffield Assay Office works within the framework established by the BHC.
• National Association of Jewellers (NAJ)minorOthersProfessional membership body representing over 2,000 members across every aspect of the jewellery industry. Sheffield Assay Office is referenced as a resource for JET students and members who purchase Bradbury's Book of Hallmarks.
• Goldsmiths' CompanycoreStrategic or Co-development PartnerThe Goldsmiths' Company is one of the Great Twelve Livery Companies of the City of London and has played a central role in the UK's hallmarking system for almost 700 years. Sheffield Assay Office maintains a longstanding relationship with the Goldsmiths' Company, hosting visits from the Prime Warden and collaborating on industry initiatives.
• Hallmarking ConventioncoreOthersInternational treaty (signed Vienna 1972, entered force 1975) providing recognised alternative to traditional UK hallmarks. The UK has been a signatory since 1972. Sheffield Assay Office can strike Convention Hallmarks as an alternative to UK hallmarks, recognised by all member countries.

Scale indicators6 records

Recent moves12 records

Expansion highlights6 records

Direct peers

• London Assay Office (Goldsmiths' Company Assay Office): One of the other three UK statutory assay offices, operating under the Goldsmiths' Company since 1300. Directly comparable in service scope (hallmarking, analytical, Convention Hallmarks) and statutory basis, with the same Hallmarking Act mandate. Closest direct peer for hallmarking volume and prestige positioning.
• Birmingham Assay Office (AnchorCert Analytical): One of the other three UK statutory assay offices, with AnchorCert Analytical providing the testing and analytical counterpart. Direct competitor for hallmarking volumes from the Birmingham Jewellery Quarter and comparable in commercial positioning.
• Edinburgh Assay Office: The fourth UK statutory assay office, serving Scotland and northern England. Directly comparable in statutory scope and service mix, and a peer for Scottish hallmarking volumes.

Broad incumbents

• Gemological Institute of America (GIA): Global leader in diamond and gemstone grading and certification. Comparable for the Diamond Verification Services (DVS) line, where Sheffield addresses natural vs. lab-grown authentication, though GIA operates at vastly larger scale and breadth across gemology.
• International Gemological Institute (IGI): Global gem certification body with diamond and gemstone grading. Comparable for DVS, offering grading reports and lab-grown identification, though broader in product and geographic scope than Sheffield's specialized offering.
• Bureau Veritas: Global testing, inspection, and certification (TIC) major. Comparable for the UKAS-accredited analytical services line (mercury screening, nickel-free testing, environmental testing), though Bureau Veritas operates across all industrial verticals at much larger scale.
• SGS: Global leader in testing, inspection, and certification. Comparable for precious metals and materials testing capabilities, competing for the same healthcare/medical device and industrial analytical testing customers.
• Intertek: Global TIC provider with significant analytical testing capabilities. Comparable for the analytical services line, particularly for medical device, environmental, and materials testing customers.

Regional players

• HRD Antwerp: Belgian-based diamond grading and certification laboratory. Comparable for the DVS line, with similar focus on diamond authentication; operates primarily in the European market and does not overlap in UK hallmarking.
• Gübelin Gem Lab: Swiss-based gem testing laboratory specializing in origin and authenticity determination for colored stones and diamonds. Comparable for analytical-grade gem testing and provenance services, though focused on the high-end Swiss/European luxury market.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/AssayOffice

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sheffield Assay Office