What Does 958 Mean on Silver? Britannia Explained

The number behind the number

The punch reads 958 but the legal standard is 958.4 parts per thousand. That awkward figure is a survival from the old troy reckoning: the standard was defined as 11 troy ounces and 10 pennyweights of fine silver in every troy pound, which works out at 95.833 per cent. Schedule 2 of the Hallmarking Act 1973 still lists the four permitted British silver standards as 800, 925, 958.4 and 999.

Against sterling at 925, Britannia is only about three and a half per cent finer. That small gap is the whole difference in metal terms, and it matters far less than most people expect when a piece is sold by weight.

Why Britannia silver exists at all

It was a currency measure, not a quality initiative. By the 1690s English silver coinage had been clipped and melted so heavily that the Great Recoinage of 1696 was needed to replace it. Part of the problem was that silversmiths could buy coin, melt it, and work it straight into plate at the same sterling standard, at a profit. The Standard of Wrought Plate Act raised the standard for wrought plate above the standard of the coinage from 1697, so melting coin no longer produced usable metal without adding scarce fine silver to it.

The marks changed with the standard. The lion passant was replaced by the figure of a woman commonly called Britannia, and in London the leopard head office mark was replaced by a lion head erased, a lion head in profile with a ragged torn neck rather than a smooth cut.

Why it did not last

Silversmiths disliked it and said so. At 958 the metal is noticeably softer than sterling, harder to raise and chase without distortion, and quicker to wear in service. Sterling was re-authorised for silversmiths from 1 June 1720 and Britannia became optional. It has stayed optional ever since.

958 on modern work

Since 1999 the millesimal number is the compulsory fineness mark and the Britannia figure is optional alongside it, so recent Britannia-standard work is usually marked 958 in an oval with a sponsor mark and an office mark. Modern silversmiths choose it where the whiter colour and the way high-purity silver takes a raised form outweigh the softness, so it turns up on studio hollowware, presentation pieces and some fine jewellery.

The Britannia coin, and the confusion it causes

The Royal Mint has issued a one-ounce Silver Britannia bullion coin since 1997, and its fineness changed partway through the run. Issues from 1997 to 2012 were struck in Britannia standard silver at .958, with a gross weight of 32.45 grams so that the coin carries a full troy ounce of fine silver. From 2013 onwards the coin has been struck in .999 fine silver at 31.21 grams. The face value is £2 throughout.

Both carry the same one ounce of silver, so the metal value is the same. The gross weights differ because the older coin needed more alloy to hold the same fine content. If you are weighing a mixed group of Britannias and the numbers look inconsistent, the date is usually the explanation. See sell silver coins for how coin lots are handled.

What 958 is worth in principle

The calculation is the same as for any solid silver: weight multiplied by fineness gives the fine silver content, which is then valued at the market rate for the day less a margin for assay, refining and handling. At 0.958 against sterling at 0.925, Britannia yields about 3.6 per cent more recovered silver per gram, which is real but modest. On a single christening mug it is pennies. On a heavy service it is worth having.

What moves the figure far more is total weight, whether the piece is weighted or filled, and whether it has value as an antique. Offers depend on inspection, weight, purity, hallmarks, stones, condition and the market rate on the day.

How to recognise Britannia silver

• Look for a seated female figure in profile holding a shield and a spear, struck small in a shaped surround as part of a row of punches.
• On London pieces from the compulsory period, look for a lion head erased in place of the usual leopard head office mark.
• On anything made after 1999, look for the number 958 in an oval surround.
• Do not read a decorative Britannia figure as a hallmark. Assay punches are small, struck into the metal, and sit in line with the sponsor and office marks.
• Check the date letter against the office. A 1697 to 1720 combination is worth having identified properly before the piece is treated as metal.
• If the marks are rubbed, photograph them at an angle under a single light source rather than flat, which makes shallow punches far easier to read.

What happens when you post 958 to us

Items are sorted by standard, XRF-assayed and weighed, and the written offer sets out the purity found, the weight and the rate used for each piece. Anything that looks like period Britannia plate, named-maker work or a complete original service is flagged in that offer rather than melted, so you can take it to an auction house or a specialist dealer instead. Decline the offer and the tracked return costs you nothing.

Accept it and payment is by Faster Payments within one working hour of acceptance, usually within 30 minutes during working hours. Parcels travel by Royal Mail Special Delivery Guaranteed, and cover may be available up to £2,500 depending on the postal method and cover level used. Sell silverware covers canteens, services and weighted pieces in more detail.

Common questions

Related guides

Reference pages

• Gold price today, UK rates
• Silver price today, UK rates
• UK gold hallmark guide
• How we value gold