Apple claims that allowing developers to distribute apps outside its official App Store would “expose users to serious security risks”.
A new report from the company argues strongly against allowing so-called sideloading of apps.
The report suggests a range of hypothetical problems including ransomware and financial scams.
It comes as Apple is under pressure from regulators and some developers over its App Store.
The company is awaiting the outcome of its legal battle with Epic Games over what the games studios says are unfair terms set by Apple.
Epic Games has made no secret of its ambition to create a competing storefront – but Apple does not allow third-party app stores to be downloaded from its own App Store.
Separately, Apple is under investigation in the EU, UK, and US over its App Store policies, as an increasing number of developers have spoken out against the so-called “Apple tax” over the past year.
Similar allegations are lodged against Apple’s main rival in the space, Google, which is also embroiled in a legal battle with Epic Games.