IAS 18 inconsistent with the Conceptual Framework:
Inconsistencies arise between the Conceptual Framework and IAS 18 in regards to the revenue recognition criteria. While there is a distinction between the definition of income and the revenue recognition criteria for income under the framework (under the asset/liability model of the Conceptual Framework) the only key difference between the two is the test of reliable measurement. If there is an increase in an asset or liability resulting in an increase in equity, income arises: provided it can be reliably measured.
IAS 18 specifies the circumstances in which these criteria will be met. This means that IAS 18 does not strictly follow the asset/liability model because it imposes additional revenue recognition criteria beyond those in the Conceptual Framework, which are not always consistent with the asset/liability model.
Further, the Appendix to IAS 18 provides numerous examples of transactions involving the sale of goods and the rendering of services. These examples are not always consistent with the standard and appear to be based on US GAAP rather than on IAS 18. For example, example 9 in the Appendix dealing with real estate sales indicates that the seller considers the ability of the buyer to complete payment. This contradicts paragraph 24 of IAS 18 (Example 9 was removed by IFRIC in late 2008).