Should the UK decide to join the euro, it would face a logistical nightmare. Coins and notes weighing hundreds of tons would have to be moved into place for E-Day, and tens of thousands of vending machines and automatic teller machines would have to be converted for the new currency.

Retailers would have to change their price labels and tills, while all firms would have to redo their accounts.

This would cost a lot of money, and in the eurozone fans and critics of the new currency still argue whether the euro's benefits really outweigh the cost of introducing it.

At least on the logistics front, the UK should be able to rest easy. No country encountered major problems, neither in the hyper-efficient north nor in the Mediterranean south.

The eurozone had a simple solution: most coins were brought into circulation through retailers, who simply gave euro change to bills settled in national currencies