Sign in with Apple" broke after update–losing data for a third of users (aso.dev)
What exactly happened?
• Apple began returning a completely new userIdentifier for existing Apple IDs, without users initiating any changes. This effectively made user authentication impossible, as we can no longer match users to their existing data. • The email field now always returns null. Although this behavior is typical for subsequent sign-ins, it’s irrelevant in this case because the userIdentifier itself changed, leaving no way to identify existing accounts. • Previously issued relay emails (@privaterelay.appleid.com) no longer accept emails—we verified this with bounce tests. • Users also report that our app has disappeared from their Apple ID’s authorized apps list.
Important context:
• We migrated our Apple Developer account from Individual to Organization about a year ago. • Everything worked perfectly until the May 3, 2025 update. • The incident occurred precisely on the day Apple released updates to the Developer Console (Accounts, Profiles, etc.). We strongly believe these internal changes at Apple triggered the issue.
Consequences:
• Every user received a new userIdentifier, meaning our system sees returning users as entirely new, breaking the link to their historical data. • One-third of our users, who registered via Apple’s private relay email, are now completely unreachable: • We can’t contact them (emails bounce). • We can’t restore their access (new IDs don’t match old accounts). • We have sent three support requests to Apple via email—no reply or acknowledgment yet, with no escalation path or live chat available.
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We were fortunate because ASO.dev also supports an alternative sign-in method (email with a one-time login code). Without this alternative, we would’ve permanently lost access for every user who originally signed in with Apple.
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We’re openly sharing this story to:
• Warn developers who rely solely on Apple Sign-In and relay email addresses. • Connect with others who’ve faced similar issues—let’s share experiences. • Draw Apple’s attention to this critical problem—currently, there is no documented solution and no available support.
Never rely solely on Apple ID authentication. Always implement a fallback method, as even major ecosystems can fail unpredictably.
20 comments
[ 3.2 ms ] story [ 60.1 ms ] threadIf you were starting over what would you do differently?
If we were starting over, we’d make that update flow more prominent from day one. Apple’s “Hide My Email” sounds harmless until it silently breaks everything later.
Forcing users to use certain identity providers while uninformed as a sole point of failure is a challenge.
Apple (or other providers) already have the user with an ID, having the app do the bidding of propagating it's use further is a different issue.
If it was optional, and a convenience/preference that could be added, that would be a different thing.
M365 login specifically can hook into quite a bit of organization information along with the user itself that can help configure apps, wouldn't be relevant for Apple in those kinds of B2B scenarios.
Apple ID is almost always a personal or individual one.
It can be convenient for sure, makes me think about how there's other things where Apple is/was the only choice for the most part like payments, although that's changed for the time being.
Most people are where they started, whether its Microsoft, Gmail, Apple, etc.
How does that work if according to you the apple private relay emails bounce?
> One-third of our users, who registered via Apple’s private relay email, are now completely unreachable: • We can’t contact them (emails bounce). • We can’t restore their access (new IDs don’t match old accounts).
You could temporarily let these emails let a one time sign in link get sent to another email account, so they can update their settings, no?
Overall, pretty serious incident. Please post updates regarding apples response.
Otherwise, how do you verify the user is requesting the one-time sign in and not a threat actor trying to associate the account to their own email?
That said, any sensitive data in our service is either encrypted with a user-provided phrase or never sent to our servers at all. We’ve put a lot of effort into security, but we honestly didn’t expect this kind of curveball from Apple — where the login email they issued suddenly becomes invalid and breaks access.
We’re waiting for a response from Apple and exploring safe fallback options in the meantime.
The good news is that Apple’s private relay addresses are unique per user, so if someone contacts us, we can match and update their account to a regular email. We’ve added a banner to our site to help guide affected users through this.
One-time sign-in via email still works for everyone else, and we’re looking into ways to let users securely update their email via support if they can no longer log in.
We’re waiting on a response from Apple and will post updates as we get them. Thank you!
Seriously, just use Argon2id or scrypt.
Any “fallback” is just you doing what you should have to begin with.
So yeah, lesson learned — don’t outsource identity fully. We thought Apple Sign In would be convenient, but it backfired hard.
Create an account via the settings page? Had to contact support because my phone number + email got stuck in some "halfway activated but can't log in" state.
Sign into the App Store + downloading some software? Got stuck in some broken form that wouldn't let me enter payment information. Had to crawl through reddit threads about how to work around this mess, just to be able to use the App Store.