Hi,

In the average costing approach, the cost of a product is determined by averaging all of its purchasing costs. The system records the many purchase prices you pay for a product and determines the average cost based on those prices.

However, the system cannot recalculate the average price for that particular purchase date if you record a transaction with a backdate. The current average cost as of the current date can be used in its place.
Eg:
Assume you bought Product A with the following prices on different dates:

June 1, 2023: 10 units at $10 each
July 1, 2023: 20 units at $5 each
The average cost would be ((10 * $10) + (20 * $5)) / (10 + 20) = $6.66 per unit.Now, if you retroactively buy 5 units on June 1, 2022, the average price on July 1, 2023, would still be $6.66 per unit. The average cost for earlier periods is not recalculated by the system using the new backdated purchase.

consider utilizing a different costing approach, such as the First-In-First-Out (FIFO) or standard- method, which expressly assigns costs based on the actual purchase order dates, if you require exact historical cost information for specific dates.

Hope it helps