1996 Treasure Act

All detector users should be aware of the legal obligations placed upon them by the Treasure Act 1996, which came into operation on the 24 September 1997 and replaced the old common law of 'Treasure Trove'.  The Treasure Act 1996 reduced the precious metal content qualification for treasure, for both coins and single artefacts, to 10% of the total metallic component. It also removed the need to show that treasure had been hidden with the intention to return and recover it.
Single precious metal coins found in isolation were removed from the definition of treasure, but groups of more than nine non-precious metal coins, when found together, were added. At the same time the Act introduced a general age qualification for treasure of 300 years. Any non-precious metal items which can be identified as associated with the treasure will now be classed as part of treasure.  This could be a bronze purse bar, clay pot or even just one bronze coin. For example, a small hoard comprising of two silver coins and one bronze coin, over 300 year old, would all be treasure.
The Act contains a provision whereby finds which are less than 300 year old can also be defined as treasure.  However, the qualification contained in the Act is that, if such finds had been made before the commencement of the Treasure Act 1996, they would have been declared, at inquest, to be 'Treasure Trove' under the old common law.  This might involve a hoard of coins, or artefacts, containing more than 50% precious metal. The 'Treasure Trove'? verdict would also have required that the find was shown to have been hidden with a view to recovery, and for which the present owner was unknown.  This could be, for example, a present day find of a hoard of Victorian sovereigns, or even pre 1947 florins. It is important to remember that the Act is not retrospective. Whilst a second (or more) gold or silver coin over 300 years old, found some time later at the same find spot as an earlier find of a single similar coin, is likely to be treasure, the second coin(s) will not, retrospectively, make the first coin treasure.
 

There are interpretations of what is meant by "part of the same find".  Two coins of gold or silver found together, but not originally in circulation at the same time, might not be classed as treasure, unless they were considered to have been deposited in the same place for a similar purpose (e.g. votive offerings). If you believe you have found treasure, you should report it to the coroner for the district in which the find was made, within 14 days of becoming aware of what you have found.  If you take it to a museum for identification, make sure you get a receipt in exchange, and tell the coroner if you are advised it is likely to be treasure.  Do not leave it to the museum to advise the coroner.  The legal responsibility is yours. Always make sure you keep the landowner fully informed. 
If you have any doubts or queries about procedure, you might consider contacting the NCMD.