What currency symbols stand for
A currency sign is shorthand for a currency's name, and many grew out of letters. £ is a stylized L for the Latin libra, ¥ is a Y with bars for yen, € is based on the Greek epsilon, and ₹, the Indian rupee sign adopted in 2010, blends the Devanagari letter "ra" with a Latin R. New signs keep arriving: ₿ for bitcoin was added to Unicode in 2017.
Some signs are shared. $ is used for the US, Canadian, Australian and many other dollars, and for the pesos of Mexico, Chile and Colombia; ¥ is used for both the Japanese yen and the Chinese yuan. When the difference matters, use the three-letter ISO 4217 code (USD, CAD, EUR, GBP, JPY, CNY, INR) or a prefix such as CA$ or A$.
Where the currency symbol goes
In English, the symbol goes before the number with no space: $25, £25, €25, ¥2,500. Many European languages put the euro sign after the number with a space and use a decimal comma, so the same price is 25,00 € in German or French. Japanese prices are often written with the character 円 after the number: 2,500円.
Three-letter codes take a space: USD 25 or 25 USD. The cent symbol goes after the number (99¢), but never mix a dollar sign and a cent sign in one price; $0.99¢ literally means less than one cent. In a list or table, keep one style and line amounts up on the decimal point.
How to type currency symbols
On Windows, hold Alt and type on the number pad: 0128 for €, 0163 for £, 0165 for ¥ and 0162 for ¢. On a Mac with the US layout, press Option + Shift + 2 for €, Option + 3 for £, Option + Y for ¥ and Option + 4 for ¢. More codes are on the Alt codes page.
On iPhone, the #+= symbols page shows € £ ¥, and a long press on $ offers more signs. On Android, Gboard keeps £ ¢ € ¥ on its second symbols page. For anything else, such as ₹, ₩ or ₿, copy it from this page, or in Word type the hex code (for example 20B9 for ₹) and press Alt + X.