Change signing key, keep packagename

Question

I cant seem to find the answer to this: Is it possible to change signing-key but still use the same packagename? So that the people who bought my app can \"re-download\" the

Answer 1

No. If you have an APK signed with a signature and containing a package name installed on a device, any subsequent apk with the same package name must have the same signature.

Answer 2

As of 2019

Yes, you can do this in some cases.

If you've enabled Manage Signing Key by Google then your signing key will be managed by Google and you can add an additional Upload Key which you can change/update if necessary. Google recommends this procedure and this procedure is available for new apps and already published apps.

If you are managing signing key by yourself you can still upgrade the signing key only once in the whole lifetime of the app. Users with the previous key will be able to use and update the app with the legacy signing key and the new users will be enabled with the upgraded key. Here is what quoted in the reference:

In some circumstances, you can request an app signing key upgrade. Your new key is used to sign new installs and app updates. Your legacy app signing key is still used to sign updates for users who installed your app before the key upgrade.

Each app can only have its app signing key upgraded once in its lifetime. In the unlikely event that you have multiple apps using the same signing key specifically to run in the same process, you won’t be able to use key upgrade for those apps.

Details is explained here