Is this an iOS, MacOS, WatchOS app? And do you have the source code in an Xcode project? Has the app already been published and this is an update? Or is this first time. Happy to help -Dean Reyburn, Reyburn Engineering, Inc. reyburnengineering.com

Hi there, You're on the right track in wanting to retain full control of your Apple Developer account while working with a freelancer. The best and most modern approach is to add the developer to your App Store Connect account with the Developer role. This allows them to access the necessary signing tools in Xcode without needing your personal credentials, and they can submit the app directly through App Store Connect. Sharing certificates and private keys (as your developer suggests) can be risky and is no longer considered best practice. Instead, you should handle signing through Xcode and App Store Connect, which ensures both security and control. This way, your app remains under your Apple Developer account, and you retain long-term control while allowing the developer to work without compromising security. Hope that helps! -Dean Reyburn, reyburnengineering.com iOS/MacOS app developer

Do you have access to the latest source code for your project? That's really the key question here. I agree with the poster above — when I've done development in the past, the app owner has their own Apple Developer account and invites the developer to join their team. The app should be submitted to App Review through the owner's account, not the developer's. A couple of other things to be aware of: if the annual Developer Program fee isn't paid and the account lapses, Apple will remove your app from the store. Once that happens, it's much harder to recover, so time is important here. Also, check any contracts you have with the development company. You may have rights to the source code, which could matter if the company's assets are being handled through bankruptcy proceedings. Without the source code, you'd essentially be starting over from scratch. The good news is that if you do manage to get the code and set up your own developer account, Apple has an app transfer process in App Store Connect that can move the app from one account to another — so you wouldn't have to lose your existing ratings and reviews. I'd definitely follow the advice to contact Apple Japan through Contact Us as a first step. Good luck! Dean Reyburn, iOS/MacOS developer reyburnengineering.com （上記は英語で書いていますが、ご質問に対するアドバイスです。翻訳ツールをご利用ください。）