Use the major currency unit before the amount. Don’t use decimals unless using smaller units.
In a sequence of numbers, use the same number of decimal places, even if every number doesn’t have a smaller unit.
£10.43 rising to £12.00.
Don’t use “0.xx million” for amounts less than 1 million, unless in a sequence of numbers.
£3.5 million, £6.5 million and £0.9 million
Write out the smaller unit in full.
Currency should use lower case.
The euro is stronger than the pound.
Write out currency as “British pounds”, or “American dollars”.