A unit is anything you can express an operation in. In most cases, this is a currency, but it can also be a stock, or even a car or a house. A unit has different values over time, its value being express in another unit. Example: the ACME stock is worth 31.2$ on January 2009.

Editing units can be done in different ways:
- Standard
This mode allows you choosing amongst the set of predefined units which one you would like to add to the current document.
- Manual
This mode allows you creating your own unit. Parameters to be provided are:
Name: the comprehensive unit name.
Symbol: the unit symbol, displayed in most tables and drop down boxes.
Type: see Unit Types.
Reference Unit: the (other) unit used to compute value of the (current) unit. For example, if you have EADS shares, and want to see their value in euros, you should select € as reference unit in EADS unit.
Country
Internet Code: The yahoo Internet code for this unit. If given this code, Skrooge is able to download the unit values from yahoo.
- Values
This edition mode allows to download unit values from Internet, or to manually enter a unit value at a given date.
Even if Skrooge considers just about anything as a unit, it makes a distinction depending on their type:
- Primary Currency
This is the currency that will be used for displaying real operations amount.
- Secondary Currency
If defined, the value in the secondary unit will be displayed upon hovering over an operation amount.

- Currency
Any currency, with no specific role for display.
- Share
This type of unit can be used for managing shares.
- Index
A stock exchange index, such as the Dow Jones, Nasdaq, CAC40, SBF120...
- Other
Any unit that doesn't fit in the above types.