Allocated storage means specific bars or coins are assigned to the owner, often with serial numbers or clear inventory records. The customer has a direct claim to identified metal rather than a general claim against the storage provider.

Unallocated storage usually means the customer has a claim to a quantity of metal, but not specific pieces. It can be cheaper and easier for institutions to manage, but it introduces more counterparty and balance-sheet risk.

For stackers seeking maximum ownership certainty, allocated or personally held metal is usually preferable. Unallocated accounts may be useful for convenience or lower cost, but they should not be confused with holding specific physical bullion.