IFRS 15 establishes a single and comprehensive framework which sets out how much revenue is to be recognised, and when. The core principle is that a vendor should recognise revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the vendor expects to be entitled in exchange for those goods or services.
Revenue will now be recognised by a vendor when control over the goods or services is transferred to the customer. The application of the core principle in IFRS 15 is carried out in five steps:

Effective date

The effective date of IFRS 15 is annual periods commencing on or after 1 January 2018. There is a choice of full retrospective application (i.e. restating comparatives as if IFRS 15 had always been in force), or retrospective application without restatement of prior year comparatives, with a number of reliefs and practical expedients. If comparatives are not restated, the cumulative impact of adoption being recorded as an adjustment to equity at the beginning of the accounting period in which the standard is first applied (the date of initial application).