Hi David,This means that you have overstated your cost of sales throughout the period, thus you need charge the credit to your Income statement. Typically it would go to a stock revaluation account on the P&L. I also would advice that you review your standard prices on a regular basis, maybe quarterly to avoid shocks to management with massive profits which might not have been expected throughout the year. Furthermore this can also have an impact on other strategic decisions like dividends, but you can addressed this by regular reviewing standard prices. The only problem with regular review of standard prices is that it can hide inefficiencies.