Why does the gross method of recording sales discounts require an adjusting entry at the end of the fiscal period?

Gross Method

An accounting practice for recording purchases with a discount, where the purchase is initially recorded at gross amount with the potential discount noted separately.

Sales Discounts

A reduction in the price of goods or services offered to a customer, intended to encourage prompt payment or increase sales.

Adjusting Entry

An accounting entry made into a company's general ledger at the end of an accounting period to record any unrecognized income or expenses for the period.