[1][2] Caixa dois includes methods to evade taxes by misrepresenting income.
Mechanisms for manipulation include failing to invoice, or documenting different financial amounts or goods and services than in transactions that actually occurred.
Caixa dois practices may also be used by larger businesses or public entities to disguise the source of or the use of funds.
[3] For example, a slush fund may be used to hide payments for illegal services such as bribes to win contracts or access to privileged information to which the payee is not entitled.
In Portugal saco azul [6] is a term used to refer to the same concept as caixa dois.