Do you run a business (trade) in Germany and earn more than EUR 24,500 per year?
Then you are obliged to submit a trade tax return to your tax office. In it, you declare how much your trade income was in the past calendar year (assessment period). You submit a trade tax return for each assessment period in which you operated your trade (annually). You must submit the declaration electronically, for example via www.Elster.de. In doing so, you declare further additions or reductions based on your profit or loss (simplified: income minus expenses).
You also specify the municipality in which you operate your business.

The tax office will send you a notice of the trade tax assessment amount by mail.
The tax office determines the trade tax assessment amount by multiplying the trade income by the tax assessment figure of 3.5 percent. This measurement amount is the basis for the amount of trade tax.

The tax office informs the municipality in which you operate your trade about the trade tax measurement amount.

The municipality sends you a notice by mail about the trade tax to be paid by you or to be refunded to you by the municipality.
The municipality calculates the trade tax from the trade tax assessment amount of the tax office multiplied by the municipality's trade tax assessment rate. Each municipality determines its own assessment rate.

With the trade tax assessment notice, the municipality also decides on the advance payments of trade tax to be paid by you in the future for the subsequent assessment period. You will receive a notice by mail about the advance payments to be made for the trade tax.

You pay the amounts specified in the notice on trade tax and/or advance payments for trade tax to the municipality on the date specified therein.