Abstract
Finnish accounting regulation allows firms a lot of discretion in affecting net profit, e.g. via tax depreciation on fixed assets and changes in untaxed reserves. The Tax Authorities use the net profit as a basis when calculating taxes for the period. This means that tax planning plays a central role in developing financial statements. The planning requires a lot of expertise and is often a difficult and time‐consuming task, especially for less experienced accountants. The author has built a knowledge‐based system to aid in developing the financial statements for limited companies. The usability of the system for inexperienced accountants has been tested and the system and the test conducted is described. The results of the test show that the system is of considerable help for inexperienced accountants.