Ad Hoc Distribution — what it is, iOS testing limitations

What is Ad Hoc Distribution?

Ad Hoc Distribution is a method of distributing iOS applications available to all Apple Developer Program members ($99/year). It allows installing apps directly on devices without going through App Store moderation. The main purpose is pre-release testing: developers, testers, and clients can install the app on their devices before the official release.

Ad Hoc Distribution uses a Provisioning Profile that includes a list of allowed device UDIDs. When signing the app, Xcode or Fastlane creates an IPA file that can only be installed on devices from this list. Each UDID is added through the Apple Developer Portal, and the total cannot exceed 100 devices per developer account.

According to Apple (2025), Ad Hoc Distribution remains in demand for pre-release testing when the app has not yet passed App Store moderation but already needs to be shown to a client or tested on real devices. However, Apple recommends using TestFlight for large-scale beta testing, leaving Ad Hoc for small groups and special cases.

How does Ad Hoc Distribution work?

Ad Hoc distribution works through OTA (Over-The-Air) installation or via iTunes/Finder. The developer creates an Ad Hoc Provisioning Profile with selected UDIDs, signs the app with this profile, and exports the IPA file. The user installs the app through Safari via a link or through Finder on macOS.

Technically, Ad Hoc Distribution involves several stages. First, the administrator collects UDIDs of test devices — each UDID is a unique 40-character identifier for an iOS device. Then the UDIDs are added to the Apple Developer Portal, a Provisioning Profile is created, and a signed IPA is generated. The validity of an Ad Hoc profile is one year, after which the apps stop opening.

# Fastlane — automate Ad Hoc Distribution
lane :adhoc do
    match(type: "adhoc")
    gym(scheme: "MyApp",
        export_method: "ad-hoc")
    pilot(
        distribute_only: true,
        devices_file: "./devices.txt"
    )
end

To install an Ad Hoc app, the user must trust the developer's certificate on their device. To do this, in iOS settings go to "General" → "VPN & Device Management" → "Profile" and tap "Trust". Without this step, the app will not launch.

UDID registration and the 100-device limit

UDID (Unique Device Identifier) is a unique identifier for each iOS device. For Ad Hoc Distribution, you need to collect the UDIDs of all test devices and add them to the Apple Developer Portal. The maximum is 100 devices per developer account per year. This limit applies to all apps of the developer, not to each app individually.

The 100-device limit resets at the end of the calendar year — the reset occurs on January 1. However, Apple recommends using TestFlight for large-scale testing, which supports up to 10,000 external testers. Ad Hoc Distribution since 2022 remains relevant for cases when the app has not yet passed Beta App Review or when testing requires access to the original IPA file.

Setting up Ad Hoc Distribution

Setting up Ad Hoc Distribution is done through the Apple Developer Portal and Xcode. The process includes registering devices, creating a Provisioning Profile, signing the app, and exporting the IPA for distribution. For team development, it is recommended to use Fastlane or automation via CI/CD.

1. Collect UDIDs of test devices via udid.io or a configuration profile
2. Add UDIDs to the Apple Developer Portal → Certificates, Identifiers & Profiles → Devices
3. Create an Ad Hoc Provisioning Profile for the required Bundle ID, including the registered devices
4. Sign the app with the Ad Hoc profile in Xcode: Product → Archive → Distribute Ad Hoc
5. Export the IPA file and distribute the link via an OTA server or Firebase App Distribution
6. For the user: open the link on the device, install the app, trust the certificate in settings

To simplify the process, distribution services are used: Firebase App Distribution, Microsoft App Center, or BuddyBuild. These services automatically manage UDIDs, create Ad Hoc profiles, and send invitations to testers. Firebase App Distribution also integrates with CI/CD pipelines via Gradle or Fastlane.

An important nuance — UDID updates. If you need to add a new device to the profile, you will have to recreate the Provisioning Profile and re-sign the app. Devices that have already installed the app will continue to use it until the profile expires (1 year). After that, reinstallation with a new profile is required.

Ad Hoc vs TestFlight and Enterprise

Ad Hoc Distribution is just one of three ways to distribute iOS apps without the App Store. TestFlight (free, up to 10,000 external testers) and Enterprise Distribution (no device limit, for enterprise apps) solve related tasks with different limitations and requirements.

TestFlight is Apple's preferred method for beta testing. It does not require collecting UDIDs, supports up to 100 internal and 10,000 external testers, automatically manages versions, and provides installation analytics. However, TestFlight requires passing Beta App Review for external testers, which can take 1–2 days. Ad Hoc Distribution requires no moderation at all.

Enterprise Distribution is suitable for enterprise apps with an unlimited number of devices, but requires enrollment in the Apple Developer Enterprise Program ($299/year) with a D-U-N-S number. Ad Hoc is available to all members of the standard program ($99/year) and does not require legal company verification. For small teams and projects, Ad Hoc remains the simplest way to distribute without the App Store.