There are different VAT scenarios
VAT-Light Registration:
If you are invoicing B2B to EU companies, or have expenses from EU companies, you *must* be VAT-Light registered and file a VAT Return and Souhrne Hlaseni for that month. No transactions in a month = no filing for that month.
Also if you receive income from online platforms such as BOLT, AirBnB, Google, Amazon, Etsy, eBay etc a VAT-Light registration and Trade License is required in case they send you money from another EU country (usually Ireland or Estonia)
Full VAT Registration:
If you make more than 2.54M / 12 months from CZECH clients, you have to register for Full VAT Registration and file a VAT Return and Kontrolne Hlaseni. This always starts as a monthly obligation. In case you only have Czech expenses but no revenue (yet), you CAN NOT register for Full VAT.
Foreign Company, Czech VAT Registration:
If you have a foreign company, but need a CZECH VAT number, you have to register for Full VAT Registration and file a VAT Return and Kontrolne Hlaseni. This always starts as a monthly obligation.The registration is a special one and requires translation of the foreign company documents - hence the higher fee.
No VAT Registration required:
If you invoice outside of EU: no VAT registration required
If you invoice private clients in the EU: no VAT registration required