I incorporated a company 2-3 years ago to sell iPhone apps through. Subsequently I became a contractor and began selling my services through the company which is great. However the name, which felt appropriate for the App Store, now just feels a little embarrassing. The company currently has a couple of contracts which refer to it by name (obviously) - one of which will be a real pain to get the other party to sign again. If I change the name of the company now how long can I legally keep trading under the former name? I have about 2-3 months left on the difficult to re-sign contract - so I could wait it out. But it's where most of my revenue comes from and so I'm looking to find a new customer to replace it right now and want to do so under the new name.