That doesn't sound correct. UG is identical to the GmbH in that regard. Do you mean a GbR?

Ahh might have confused it with one of the other forms then... It's been a while since I had to learn all that stuff.

You are confusing UG with something like GbR. UG is basically a baby GmbH with constraints of the name of the company and how much money the associates can extract from it (until the company got 25k€ captial and can become a normal GmbH).

Only up to 25k.

UG allows you to incorporate for 1eur (600eur with accountant, notary, etc) and you are liable only up to level of full GmbH which is 25k.