Yes, you can upgrade your BahnCard Business 50 from second class to first class, as well as to a BahnCard 100.

First, order a new BahnCard Business from a higher category. Then inform BahnCard Service of your wish for an extraordinary termination of your existing BahnCard. Please use the exchange form for this purpose.

The remaining value of the original BahnCard (provided it is at least 15 EUR) will be refunded to the account you specified on the exchange form.

It is not possible to convert a BahnCard Business from first class to second class, or from BahnCard Business 50 to BahnCard Business 25.