Hallmarking Explained

(UK only.International convention marks are not covered in this article).

The hallmarking act of 1973 states that:

“It is an offence for any person in the course of trade or business to:


(a)apply to an un-hallmarked article a description indicating that it is wholly or partly made of gold, silver or platinum.

(b)supply or offer to supply un-hallmarked articles to which such a description is applied.”


In other words, it is illegal to sell or describe any article as gold, silver or platinum unless it is hallmarked. (since 1st January 2010 this also applies to palladium: Hallmarking Act 1973 (Application to Palladium and Miscellaneous Amendments) Order 2009).


What is a hallmark?

A hallmark is a guarantee of quality, safeguarding the consumer, and consists of 3 compulsory marks:

1 – sponsors mark

2 – millesimal fineness mark

3 – assay office mark

Sponsors Mark - previously known as the makers mark, this is the mark which identifies the person to whom the assay office registration belongs.It would usually be the person making the article who would require the hallmark to be applied, hence ‘maker’, however it is now recognized that articles may be made on someone else’s behalf e.g. by an employee of the owner of the mark.The article would still be hallmarked on behalf of the registered person, who has become the ‘sponsor’.

Millesimal Fineness Mark – this is the numerical mark which identifies the type of precious metal and number of parts per thousand of pure metal in the alloy.

Assay Office Mark – this is the pictorial mark which identifies the assay office at which the piece was tested.There are 4 assay offices in the UK:

London (leopards head), Birmingham (anchor), Sheffield (Yorkshire rose) and Edinburgh (castle)

There are also other marks which can be added to a hallmark optionally.These are:

Traditional Fineness Mark – this is again a pictorial mark, denoting whether the article is platinum (orb), gold (crown), silver (lion passant), or palladium (Pallas Athene – Greek goddess)

Date Letter – this letter is added to show the year of hallmarking (it does not necessarily reflect the year of manufacture).A different style of lettering or font is used at the start of each revolution of the alphabet and can date a piece in a similar way to a vehicle registration number.This can be applied to any article regardless of fineness.

Under the Hallmarking Act 1973, every person “dealing” in precious metal is legally required to display the statutory Dealers Notice.(see below)



Articles below certain weights are exempt from hallmarking.These are:

  • Silver7.78 g
  • Gold1.0 g
  • Palladium1.0 g
  • Platinum 0.5 g


Common UK Fineness Marks


  • 999
  • 995
  • 950 (the most common purity for platinum jewellery)
  • 900
  • 850


  • 999 (24) carat
  • 916 (22 carat)
  • 750 (18 carat)
  • 585 (14 carat)
  • 375 (9 carat)


  • 999 (Fine silver)
  • 958 (Britannia silver)
  • 925 (Sterling silver)
  • 800




Can I hallmark mixed metals?


The simple answer is yes.


The more complicated answer is the hallmark will depend on the quantity of each metal as to what mark will be applied.


In the first instance, the item can only be marked if, in the opinion of the Assay Office, an ordinary person would be able to determine which part is which precious metal.


Each precious metal component must be at least the minimum legal fineness for that

metal, i.e. Gold 375, Silver 800, Platinum 850 (parts per thousand).

Any precious metal component which is below the minimum fineness means the article cannot be marked at all.

Exemption weights for mixed precious metals are based on the total weight of metal in the article

The standard exemption weights apply so:

All articles with a component to be described as platinum in which the total weight of all metal is over 0.5 g will need to be hallmarked.


All articles with a component to be described as palladium in which the total weight of all metal is over 1.0 g will need to be hallmarked

All articles with a component to be described as gold in which the total weight of all metal is over 1.0 g will need to be hallmarked.

All articles with a component to be described as silver in which the total weight of all metal is over 7.78 g will need to be hallmarked.

Regulations for articles of 2 or more precious metals

The full hallmark struck will be that of the least precious metal, in order, silver, gold and platinum. This will normally be struck on the appropriate metal which must be more than 50% of the weight of the article.

The fineness mark only will be stamped on the 'higher' precious metals.



Confused?Here’s an example….



A pendant is created in silver weighing 1.5 g.This is exempt from hallmarking as it is less than 7.78 g.

An accent is then added using 9 ct yellow gold, weighing 0.75 g.This on its own would be exempt as it is less than 1.0 g.

However, when the accent is applied the total metal weight is 2.25 g.When the article is advertised for sale as containing gold it instantly comes under the 1.0 g exemption limit for gold, therefore this piece must be hallmarked.

The full hallmark (sponsors mark, fineness mark and assay office mark) will be that of silver as this is the least precious metal, and the fineness mark of 9 ct gold (375) will be added to the gold accent wherever possible.


This is not intended to be an exhaustive explanation of the rules and regulations surrounding hallmarking, it is intended to give an overview and attempt to simplify the mixed metals confusion.



Article written by Linda Wear (with thanks to Sheffield Assay Office)

To see Linda's work, visit her website WiccanWear




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