Sterling is 925 almost everywhere, and almost nothing else is
Sterling silver is 925 parts per thousand pure silver, 92.5% by weight, and it is the one standard the UK, the US and India all recognise. Beyond that, the lists differ. The UK approves four standards, the US defines two words, and India’s Bureau of Indian Standards lists seven grades. A number on silver means what the law where it was struck says it means, and who verified it differs just as much.
Every figure on this page is taken from the instrument that sets it: the UK’s Hallmarking Act 1973, the US National Gold and Silver Stamping Act at 15 U.S.C. § 296, and India’s IS 2112:2025.
United Kingdom: four standards and an independent test
Schedule 2 of the Hallmarking Act 1973 sets four silver standards: 800, 925, 958.4 and 999. The 958.4 standard is Britannia silver, and the Act gives it to one decimal place, which is why this page writes 958.4 rather than rounding it. Above 7.78 grams, a silver article may not be described as silver in the UK unless an assay office has tested it and struck a hallmark at one of those standards. Under 7.78 grams, hallmarking is not compulsory.
On a UK hallmark the standard appears as the number in a shaped shield, sometimes accompanied by the traditional lion passant for sterling (in England) or thistle (in Scotland), or a seated Britannia figure for 958.4.
United States: two words with legal meanings, and no test
The US has no assay office and no requirement to stamp silver at all. What the National Gold and Silver Stamping Act does is fix the meaning of two words if they are used. “Sterling” means at least 925 parts per thousand and “coin” at least 900, each with a divergence of four parts per thousand allowed. Measured across the whole article including solder, the silver may not fall short of the mark by more than ten parts per thousand. Any other fineness may be stamped as a number and is held to the same tolerances.
The maker stamps its own work and the law holds it to the stamp. That is a real legal obligation, but it is not the same assurance as a UK hallmark, where the metal was tested before the mark was struck.
India: seven grades, voluntary, and a 2025 revision
India’s silver standard is IS 2112. The 2025 edition, applied from 1 September 2025, lists seven grades — 800, 835, 925, 958, 970, 990 and 999 — and introduces HUID-based hallmarking for silver, as already used for gold. A hallmark under the new standard has three parts: the BIS standard mark with the word SILVER, the purity grade, and the HUID, which can be checked in the BIS Care app.
Two details trip people up. Silver hallmarking in India is voluntary, unlike the mandatory gold scheme. And the 2014 edition included a 900 grade that the 2025 edition does not, so a genuine older hallmark can read 900 even though that grade is no longer listed.