As iOS developers we know, Bundle ID is a string that uniquely identifies an application in the app store. So while developing the app we have to choose unique bundle-id for our app. Apple recommends reverse domain name for this, like com.yourCompany.yourApp For the above scenario. As apple guidelines say, once your application successfully uploaded to store, you can’t change the bundle ID later. So always make sure that you choose a bundle identifier that makes sense for the project and the owner. This is one of the most frequently asked iOS basic interview questions and answers for freshers in recent times.