“Przedsiębiorca” is usually translated as “entrepreneur”. Although this is one of several possible translations, 99% of the time it is the wrong word.

First of all, look at a Polish definition of “przedsiębiorca”:

Zgodnie z definicją  zawartą w art. 43¹ kodeksu cywilnego przedsiębiorca to: „osoba fizyczna, osoba prawna i jednostka organizacyjna, która nie jest osobą prawną, a której ustawa przyznaje zdolność prawną, prowadząca we własnym imieniu działalność gospodarczą lub zawodową”.

I have underlined “osoba prawna i jednostka organizacyjna, która nie jest osobą prawną” because the key difference between “przedsiębiorca” and “entrepreneur” is that “przedsiębiorca” includes this meaning while “entrepreneur” does not.

“Przedsiębiorca” has a very broad meaning, ranging from an individual natural person who carries out economic activity to a large company.

In contrast, “entrepreneur” has a very narrow meaning. It only means an individual natural person who carries out economic activity – and is usually used to describe businessmen who built successful businesses with a great deal of initiative and risk-taking. So Steve Jobs was an entrepreneur, Virgin’s Richard Branson is an entrepreneur, Tesla’s Elon Musk is an entrepreneur, Jan Kulczyk was an entrepreneur.

If you use “przedsiebiorca” to refer to an entity rather than an individual natural person, then you cannot use “entrepreneur”.

Instead you should use one of the following, which may depend on the context. I find “business entity” is usually the best-fit:

            business entity
            enterprise
            company
            business
            economic operator
            business operator
            operator
            business venture
            undertaking

Translate rejestr przedsiębiorców as “companies register”, NOT “register of entrepreneurs”.