deductible expenses

To keep my bookkeeping administrative and simple, I would prefer not to enter all expenses, but rather a mix of fixed (whether or not lump sum) expenses and actual expenses.

For the fixed monthly costs, I include 1) the payment to Dexxter for the software package (24.20), 2) the flat rate for office costs (142.50), internet and PC (20 EUR) + car wash (15 EUR) and 3) the business lease with Cyclis Bike Lease (185.26 EUR).

For variable costs, I record receipts for coffee, books and magazines and, periodically, restaurant bills or business gifts, parking costs and municipal business taxes.

I no longer keep track of other costs, such as the depreciation of new skylights in my office or petrol, and therefore do not include them. And professional clothing is not allowed, I thought.

Is that justifiable to the tax authorities?

Kind regards.

Dirk Diels