The annual tax returns are submitted on the DOH and DOH-Z forms, for self-employed activities that determine income based on the recorded income and expenses in the KPI form. Self-employed activities records incomes and expenditures according to the cash principle. Amortization expenses are calculated in the DI form and are tax-deductible if they are within the taxable rate. Craftsmen who received government grants and incentives for the purchase of long-term assets need only to record in the receipts the amount of the accrued depreciation. Form DOH must be submitted no later than 28 February of the current year for the previous year. Income from self-employment is reduced by the amount of new workers' salaries, the amount of State aid for education and training, research and development expenditure, and the transferred loss. Income is also reduced for the amount of personal deductions of taxpayers and subsidized members and for donations and paid contributions for health insurance in the country. At latest by February 28 of the current year, the DOH form should also submit the final calculation for the obligation to pay the tourist membership fee on the TZ form, a charter rent on the SR form, the fee for the use of the general forest function on the OKFŠ form, and the calculation of the chamber contribution on the KD form. All of the above are described in more detail below.