The currency used in a country affects your application, too. Most currencies have their own currency symbol. Examples are € for Euro in Europe, £ for the British pound, or Italian lira (outdated), ¥ for the Japanese yen or Chinese Yuan, and $ for the dollar used in Australia, Canada, Jamaica, New Zealand, USA, and many others.
The currency symbol is defined in the character set used in the country. The symbol is also defined in the regional settings of the Windows control panel.
Because the symbol does not fully specify the currency as shown in the previous examples, you should use the international three-character currency codes derived from ISO 4217, like USD for US dollar, EUR for Euro and so on. If your application handles more than one currency, you should save the currency code, too.
You should be careful when you define a currency field, and exchange data with a spreadsheet or database application, like Excel or Access. These applications use the system setting. The monetary difference is quite large in the conversion, such as going from the Japanese Yen (JPY) to the US $ (USD) without currency conversion.
In addition, you should be aware that the currency code might be placed in front of, or behind, the currency value.
Be sure to check the system settings for the default currency and symbol placement. The Windows API provides functions to get the appropriate values. In .Net, check the culture name space. Be prepared and use the international currency codes. When you allow user input, make sure that the user knows which format is required.