Errors are MATERIAL mistakes in recognition, measurement, presentation or disclosures. It can arise from math, GAAP application, Oversight issues, or misusing facts. Nonmaterial items do not need adjustments.
Unlike others, retrospective adjustment is called restating prior periods.
Under GAAP, Errors are adjusted retrospectively by restating prior periods. However, under IFRS, an impracticable correction can be adjusted prospectively from earliest date practicable.
Presenting errors for non-comparative F/S is simple, adjust the opening R/E balance net of tax.
Presenting errors for comparative F/S depend on if we are showing the year error has occurred.
If we are showing it, just correct it directly on that F/S because the error is right there.
If we are not showing it, adjust the opening R/E balance of the earliest year presented.
FYI, Ending Inventory will fix itself after two years.