The best bullion prices in the world are available where the liquidity is deepest - on the international physical bullion market. Centred in London, this is where central banks, bullion banks, investing institutions, gold miners and refiners trade what are called "good delivery" bars.

These bars are a standard size: 400 ounces (12.4 kg) for gold, 1,000 ounces (31.1 kg) for silver, and between 1 to 6 kg (32.2 to 192.9 oz) for platinum or palladium. They are made by accredited refiners and kept in accredited vaults. Their movement, by accredited couriers, is carefully documented.

Because these bars' entire life is auditable, and because they have never been in private hands, a professional buyer accepts them as "good delivery" by the seller. So the seller achieves the international spot market price and gets paid quickly and efficiently.

BullionVault allows private investors access to the professional market. And that means you pay the same low costs as the professionals for buying, selling and storing large bar gold, even though most clients never own anything like a whole bar.

Coins and small bars don't come under the good delivery system, so they cannot be sold on the professional market. BullionVault only acquires coins and small bars exceptionally, to meet the specific withdrawal requests of clients.