What is the rationale behind a government establishing a de minimis rule? One reason is that it is efficient. If a very small amount or transaction is processed in the same manner as a large amount or transaction, then there is unnecessary administrative work. De minimis meaning is used for things that are considered to be of low value. A de minimis tax provision may offer a specific threshold/exception in certain situations. So, what is de minimis in simple terms? This is a rule that can provide proportional treatment to insignificant matters.