You do not need a business visa to have a trade license. With a visa or residence permit for employment, study, family or another purpose, you can register a trade license next to it.
Your main purpose must stay
The one condition: the original purpose of your stay must stay valid and remain your main activity. On an employee card, your job stays your main source of income; on a student permit, you keep studying. The trade license is extra.
That makes a trade license a good way to prepare: start invoicing while you are still employed or studying, and build up income and clients before you change anything. The foreign police take a business with a track record more seriously.
No work permit needed
A work permit (employee card) is only for employees of a Czech-based company. On a trade license you are self-employed: you invoice your clients as an independent contractor. Worked for a foreign company before you moved? Then it is usually easy to continue with them as a client.
Changing your purpose of stay to business
Do not quit your job or studies and hope to continue on a trade license. You can only change your purpose of stay to business inside the Czech Republic if you have a long-term residence permit and have lived here for more than 5 years. Exceptions: holders of the job-search / start-a-business permit (which graduates of a Czech university can get) and holders of a family reunification permit. You apply at an office of the Ministry of the Interior before your current permit expires. If it expires during the process, you start again with a business visa from an embassy abroad. See the business visa.
Keep your trade license valid for every renewal
For a non-EU citizen, the trade license registration is tied to your visa or residence permit. To extend the permit you need a valid trade license, and you can only extend while your current permit is still valid. So never let the trade license lapse, or you start from scratch.
- In the last days of your trade license validity you can ask the trade license office for a confirmation that keeps it valid for 180 more days while the ministry decides. If the decision takes longer, the trade license expires for good.
- Once you have your new visa or permit, show it at the trade license office within 3 days, or the trade license expires even though your permit is valid.
Official sources
- Business visa (Ministry of the Interior, ipc.gov.cz)
- Changing the purpose of stay (Ministry of the Interior, ipc.gov.cz)