Final answer:
Revenue from a sale should not be recognized if the buyer can return the product and the return rate cannot be reliably estimated, as it creates uncertainty about the sale's completion. Payment methods or discount prices do not inherently prevent revenue recognition if all other conditions are met.
Step-by-step explanation:
A sale should not be recognized as revenue by the seller at the time of sale if the buyer has a right to return the product and the amount of future returns cannot be reasonably estimated. This scenario creates uncertainty regarding the actual completion of a sale, leading to potential revenue adjustments in the future if a substantial number of products are returned. According to the revenue recognition principle, revenue should only be recognized when it is realized or realizable, and it is earned. If there is significant uncertainty due to the buyer's right to return and the inability to estimate returns, the seller cannot be sure that the sale is completed.
In contrast, payment by check or a selling price less than the normal selling price does not prevent revenue recognition, assuming all other revenue recognition criteria are met. Payment by check is simply a method of payment that does not affect the completion of the sale, while selling at a lower price still constitutes a completed transaction provided goods or services have been delivered and control has been transferred to the buyer.