How to read a BIS hallmark on your jewellery

In short

• Hallmarking in India is regulated by the Bureau of Indian Standards (BIS), and jewellers selling hallmarked pieces must be registered with it.
• Every hallmarked piece carries a six-character HUID code, and you can verify it yourself on the BIS Care app.
• A registered jeweller must give you the tools to check: a magnifying glass, a weighing balance and a clear bill.

A hallmark is a small stamp that tells you what a piece of jewellery is made of. It is the simplest way to check what you are buying, and it takes a minute. Here is what to look for, and what a registered jeweller must offer you.

Who sets the standard

In India, hallmarking is regulated by the Bureau of Indian Standards (BIS) under the BIS (Hallmarking) Regulations, 2018. A jeweller who sells hallmarked jewellery must be registered with BIS, and the certificate of registration must be displayed in the shop. Outside the shop, you should see the BIS logo with the words "Hallmarked Jewellery available for sale".

The rules are updated from time to time, so the BIS website is the place to confirm the latest position.

The marks on a hallmarked piece

The marks are stamped very small, usually on the inside of a ring, the clasp of a necklace or the post of an earring. They include:

• The BIS mark. A small logo showing the piece was hallmarked under the BIS standard.
• The purity grade. A number that tells you the fineness of the metal, for example 22K916 or 18K750. The number after the K is the parts of pure gold per thousand.
• The HUID. A six-character code of letters and numbers, short for Hallmark Unique Identification. Every hallmarked piece carries its own code.

Inside the shop, a registered jeweller must display the components of the hallmark and a chart showing how fineness corresponds to carat. If you are unsure what a mark means, that chart is the quickest answer.

Why the HUID matters

The HUID is linked to a record of the piece. BIS checks a code against that record, which includes the type of jewellery, its weight, photographs, the jeweller's name and the name of the hallmarking centre.

You can do a version of this check yourself. A registered jeweller must display a poster for the BIS Care app, which has a "Verify HUID" feature. Use it to confirm that the piece in your hand matches the record.

What a registered jeweller must offer you

Under the BIS guidelines for jewellers (July 2026), these must be available in the shop:

• A magnifying glass of at least 10X magnification, so you can read the marks.
• A weighing balance, preferably accurate to 0.01 g, so you can check the weight.
• The hallmarking charges as fixed by BIS.
• BIS contact details, for any query or complaint.

What the bill must show

The bill for a hallmarked piece must list:

1. A separate description of each article.
2. The net weight of the precious metal.
3. The purity, in carat and fineness.
4. The hallmarking charges.

It must also say that you can have the purity of the piece verified at any BIS-recognised assaying and hallmarking centre.

What to check when you buy

1. Look at the stamp. Ask to see the marks under the magnifying glass.
2. Match the purity. The grade stamped on the piece should be the grade written on your estimate and bill.
3. Verify the HUID. Use the BIS Care app, then keep the code with your bill.
4. Check the weight. Ask to see the piece weighed.
5. Ask if something is missing. If a piece has no mark, ask why.

A note on stones and other metals

A hallmark describes the metal only. It does not describe the stones. For stones, ask for the type, the weight and, where it applies, a certificate. We write more about that in our guide to colour stones.

If you would like a piece explained before you decide, send us a message. Our team is glad to show you where each mark is and what it means.