How to Check Gold Purity and Read a BIS Hallmark
Why hallmarking matters
Gold purity decides what you pay. A piece sold as 22K but made of lower purity gold can cost you thousands of rupees. Hallmarking is an independent check by a Bureau of Indian Standards (BIS) recognised centre that confirms the purity written on the jewellery.
In India, hallmarking of gold jewellery and artefacts is mandatory in notified districts, and the six-character HUID (Hallmark Unique Identification) code has been required on hallmarked pieces since 2023.
What a BIS hallmark shows
A modern hallmark has the BIS logo, the purity grade (for example 22K916), and a six-character alphanumeric HUID. Older pieces may also show the hallmarking centre mark and the jeweller identification mark.
Look for these marks with a magnifying glass, usually on the inside of a ring or the clasp of a chain. If a piece is too small or delicate to be marked, ask the jeweller for the hallmark details on the invoice.
What 999, 916, 750 and 585 mean
999 means 99.9% pure gold (24K), used for coins and bars. 916 means 91.6% gold (22K), the most common grade for jewellery in South India. 750 is 75% gold (18K) and 585 is 58.5% gold (14K), used for studded and lightweight jewellery.
How to verify before you buy
Use the BIS Care app to enter the HUID and confirm the jeweller, the item type and the purity registered for that piece. Check that the purity on the bill matches the hallmark on the jewellery.
Keep the invoice. It should state the gold weight, purity, stone weight if any, making charges and the HUID. A written bill is your proof if you later want to exchange or sell the piece.