On 22.10.2020, the BMF published the results of the tax audit for 2019. A reason to take a closer look at the partly dry figures.
The BMF divides businesses (including trading businesses, manufacturing businesses, liberal professions, agricultural and forestry businesses, etc.) into a total of four size categories: Large enterprises (G), medium-sized enterprises (M), small enterprises (K) and micro enterprises (KSt). The classification depends on the sales revenue or the taxable profit.

In total, the state audits had a total of 13,341 auditors at their disposal in 2019. Of the 8,225,244 establishments recorded in the establishment register, 181,345 establishments (=2.2 percent) were audited. The additional result in 2019 was 15.2 billion euros or 1,139,344 million euros per auditor. From the point of view of the tax authorities, the tax audit is therefore a worthwhile business.
It gets interesting when you look at how high the additional result per audited company turns out to be.
The 181,345 businesses audited are distributed among the size categories as follows:
Large companies = 38,876 checks
Medium-sized companies = 47,948 checks
Small businesses = 36,096 checks
Microenterprises = 58,425 checks
This Additional results are attributable to the individual size classes:
Large companies = 11.6 billion euros
Medium-sized companies = 1.2 billion euros
Small businesses = 0.7 billion euros
Microenterprises = 1.1 billion euros
Other = 0.6 billion euros
This accounts for an Additional result per individual test:
Large enterprises = 298,384.61 euros
Medium-sized companies = 25,008.34 euros
Small businesses = 19,392.73 euros
Micro enterprises = 18,827.56 euros
According to the statistics of Statista 86 percent of medium-sized companies in Germany achieved sales of up to one million euros in 2019.
The initial question can therefore be answered in such a way that the tax audit "costs" an ordinary commercial enterprise in Germany with an annual turnover of up to 1 million euros an average of 19,392.73 euros in additional taxes.