I've lived in Germany since 2005, and have been running business since 2009. There's a very complex tax system (I do my own taxes) which isn't directly comparable with UK, however corporation tax can broadly be compared with Körperschaftsteuer, of which the percentage is 15% (plus 5.5% on that 15% amount solidarity-tax). This is for larger businesses (corporations). I only have a small modest thing going, so I pay a business-tax called Gewerbesteuer, but only if I hit a certain amount of profit (which I rarely do). However corporations also have to pay this Gewerbesteuer, and if they post mighty profits, this could run the total tax-due percentage (including the Körperschaftsteuer) to around 30% maximum.
Gewerbesteuer could be translated as commercial tax, or trade tax. Or simply business tax. is there such a thing? I'm not familiar with the UK tax system...