The depot looks largely unchanged since the robbery
Five men have been convicted of involvement in the UK's biggest ever cash robbery in February 2006. But what exactly goes on at the Securitas depot in Tonbridge, Kent?
Until the robbery, most local people had no idea what the building was used for, but afterwards the depot and its operations received a lot of publicity.
Today, it still serves the same function - holding and distributing money for the Bank of England (BoE) - but it is now managed by Loomis UK, the renamed cash-in-transit arm of Securitas.
It has also overhauled its security and procedures to reduce the risk of another robbery.
In recent years, the BoE has started to use several privately owned sites to store, sort and circulate its bank notes.
As well as Securitas, they are run by HBOS, the Post Office, Royal Bank of Scotland and Securicor.
SECURITAS AND LOOMIS
In 2007, the cash-in-transit arm of Securitas was renamed Loomis
Loomis now handles the distribution, processing and recycling of cash for financial institutions, retailers and
other commercial enterprises
Loomis also operates in Europe and the US
Other divisions of Securitas are responsible for services like guarding and alarm systems
The BoE also has two distribution centres of its own, in Leeds and alongside printing works in Debden, Essex.
By using a number of different depots and private companies as part of its Note Circulation Scheme (NCS), it believes the efficiency of its operation has been improved.
It also says the practice has cut the overall financial impact of the more prevalent crime of security-van robbery.
"As there are a number of these centres, smaller amounts of money are now being transported by road," a BoE spokesman said.
The BoE says it tries to keep the volume of notes in the distribution network to a minimum needed to support the economy and sustain an acceptable quality of notes in circulation.
It can also adjust for seasonal fluctuations in the demand for cash by withdrawing surplus notes from the system to centres like the one in Tonbridge.
At the end of each working day, the BoE purchases from cash centres the volume of notes in their system.
The depots then buy them back first thing the next day.
The notes never physically change hands, but by doing this, private companies like Securitas do not bear the cost of holding the notes overnight.
That meant that when the robbery took place, the notes were owned by the BoE - but Securitas has agreed to reimburse everything that was lost.
Securitas - and now the Loomis UK arm - processes about 40% of the cash deposits made in the country.
When clients require extra money - for example if a bank needs more notes to supply its ATM machines - the company can also arrange to drop money off.
It is because so many deliveries of cash are made at the Kent depot each day, and so many consignments are sent out, that the company does not always know exactly how much money it is holding at any one time.
This made it more difficult to know exactly how much had been stolen, and a complete audit had to be done to find out.
There was also speculation the robbers may have known that February - coming just after the New Year sales - is the month when the largest amount of cash is traditionally taken out of circulation.
The robbery prompted Sir John Gieve, deputy governor of the BoE, to lead a review of security arrangements for currency storage.
He looked at all independent cash centres and the BoE's own, as well as the system of distribution itself.
In a statement, the BoE said: "The recommendations from that review have been implemented and, as a consequence, security has been improved in a number of areas."
Understandably, the BoE and Loomis UK cannot reveal the changes they have made.
But Tony Benson, head of risk at Loomis UK, said changes had been made both physically to the Tonbridge depot building and to the procedures employed there.