Android Updating Marketplace App Using A Different Signing Key

Developer signed an app with his personal keystore but it should have been the company's keystore. Is it possible to update the app in the marketplace using the company's keystore

Solution 1:

No, you will have to publish the app as a new app in the market. This time signed with the company's key. You will also have to change the package name as it is already used by the app which is already in the store.

When you try to update a app with a version that was signed with a different key Android will show an error to the user telling that the signature doesn't validate.

Solution 2:

It is impossible to change the signature now that it is in the marketplace. Google's only response will be to change the package name and upload it as a separate application.