Can I upload an iOS app with a lower version than the latest TestFlight version?

I am currently facing the following situation:

• My app is live in the App Store with version number (CFBundleShortVersion) 1.2.5.

• I plan to upload version 1.3.0 to TestFlight for testing purposes. This version will not be released in the App Store.

• The next version intended for release in the App Store will be 1.2.6.

My question is: Will I be able to upload version 1.2.6 to the App Store after having already uploaded version 1.3.0 to TestFlight?

You will be able to upload any builds, that are > 1.2.5 - the most recent published build. As the result, any version between 1.2.6 - 1.3.0 will be allowed until 1.3.0 was published. For example:

• The version available on the AppStore is 1.2.5

-> ✅ any builds which version > 1.2.5

-> ❌ any build which version <= 1.2.5

This may occur while attempting to upload a lower build version:

Invalid Version. The build with the version “1.2.4” can’t be imported because a later version has been closed for new build submissions. Choose a different version number. (ID: b36cfa2b-d5ee-4558-8fb3-aa42d6224db4)