7.3 Common Types of Transaction
7.3.1 Warranties
If a customer has the option to purchase a warranty separately from the product to which it relates, it constitutes a distinct service and is accounted for as a separate performance obligation.
If the customer does not have the option to purchase the warranty separately, for instance if the warranty is required by law, that does not give rise to a performance obligation and the warranty is accounted for in accordance with IAS 37.
7.3.2 Principal versus agent
An entity must establish in any transaction whether it is acting as principal or agent.
It is a principal if it controls the promised good or service before it is transferred to the customer. When the performance obligation is satisfied, the entity recognises revenue in the gross amount of the consideration to which it expects to be entitled for those goods or services.
It is acting as an agent if its performance obligation is to arrange for the provision of goods or services by another party. Satisfaction of this performance obligation will give rise to the recognition of revenue in the amount of any fee or commission to which it expects to be entitled in exchange for arranging for the other party to provide its goods or services.

