Look closely at a piece of gold jewellery hallmarked in India since mid-2021 and you will find a short code of letters and numbers beside the purity mark. That code is the HUID, the Hallmark Unique Identification number. This page explains what it is, where it sits among the other marks, and what it does and does not tell you, using only what the Bureau of Indian Standards, the body that runs hallmarking in India, says in its own hallmarking FAQs.
What HUID stands for
BIS describes the HUID as a Hallmark Unique Identification number and one of the components of the hallmark. In its words, it is a six-digit alphanumeric number which is unique for each hallmarked item and is traceable. “Six-digit alphanumeric” means six characters, each a letter or a number. It is not a serial number for the jeweller or the design: each hallmarked article gets its own.
The three marks on an Indian gold hallmark
According to BIS’s FAQ, since the HUID was introduced on 1 July 2021 a gold hallmark consists of three marks:
- The BIS logo, the standard mark of the Bureau of Indian Standards.
- The purity, shown as both caratage and fineness, for example 22K916.
- The HUID, the six-character code unique to the piece.
BIS’s mandatory hallmarking FAQ states that a hallmark is valid for the entire lifetime of the hallmarked jewellery, and that a consumer can sell old un-hallmarked or hallmarked jewellery they hold to jewellers.
The purity grades BIS lists
The gold standard is IS 1417:2016, “Gold and Gold Alloys, Jewellery/Artefacts: Fineness and Marking”. BIS’s hallmarking FAQ lists six grades:
- 14K585: 585 parts per thousand gold
- 18K750: 750 parts per thousand
- 20K833: 833 parts per thousand
- 22K916: 916 parts per thousand
- 23K958: 958 parts per thousand
- 24KS995: 995 parts per thousand
Two details are worth noticing. The top grade is written 24KS and stands for 995, not 999. And 22K is stamped 916, while 22 ÷ 24 works out to 916.6…: the mark states the fineness standard, and the fineness standard is what the piece is held to. The gold purity converter sets karat and fineness side by side. The list above is the FAQ’s as read on 17 October 2026; if BIS adds a grade, its FAQ is the place it will appear first.
BIS also hallmarks silver, under IS 2112, and its FAQ lists silver fineness grades separately. The HUID answers in the FAQ refer to gold, and this page covers gold only.
How to check a HUID
BIS’s answer is the BIS Care app. Its FAQ says a customer can verify the HUID number in the app using the “Verify HUID” feature, and get the information related to the jeweller’s registration number. That makes the code a way to check that a hallmark was issued through the BIS system, and to see which registered jeweller it is linked to.
What the check confirms is the record. It does not test the metal in your hand. A code that verifies on a piece that has been tampered with, or a code copied onto a different piece, would still need the piece itself to be examined; the guide to fake hallmarks covers the physical signs that a mark is not what it seems.
If the purity falls short
BIS’s mandatory hallmarking FAQ sets out the remedy under section 49 of the BIS Rules, 2018: where a hallmarked article is found not to conform to the standard, the compensation to the buyer is two times the amount of difference, calculated on the shortage of purity for the weight of the article sold, plus the testing charges. That is the rule as BIS states it; how a claim is made is a matter for BIS and its procedures, not for this page.
What a HUID does not tell you
- It is not a value. The HUID identifies a hallmarked piece; it does not price it. The gold in a piece is its weight multiplied by its fineness, and the scrap gold calculator puts today’s price on that fine gold. That figure is melt value, which is not what any buyer pays; the calculator shows the payout ranges beside it.
- It does not describe stones. A hallmark is a statement about the metal. Gemstones and their weight are outside it, and stone weight should be left out before purity is applied.
- It does not travel abroad. A BIS hallmark is a mark under Indian rules. Other countries apply their own; the guide to buying gold abroad and how UK hallmarking works explain how foreign marks are treated.