Apple Stops Signing iOS 15.3.1 Following iOS 15.4 Release, Downgrading No Longer Possible

Following the release of iOS 15.4 on March 14, Apple has stopped signing iOS 15.3.1, the previously available version of iOS that came out in February. As iOS 15.3.1 is no longer being signed, it is not possible to downgrade to that version of iOS if you've updated to iOS 15.4.

iOS 15
Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date, so it is not unusual that iOS 15.3.1 is no longer being signed.

iOS 15.3.1 was a bug fix update that addressed WebKit vulnerabilities, while iOS 15.4 was a major update that added new emoji characters, Face ID with a mask support, and tons of other features. Apple has also stopped signing tvOS 15.3.

Popular Stories

AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2, AirPods Pro 3, and AirPods 4

Thursday November 13, 2025 11:35 am PST by
Apple today released new firmware designed for the AirPods Pro 3, the AirPods 4, and the prior-generation AirPods Pro 2. The AirPods Pro 3 firmware is 8B25, while the AirPods Pro 2 and AirPods 4 firmware is 8B21, all up from the prior 8A358 firmware released in October. There's no word on what's include in the updated firmware, but the AirPods Pro 2, AirPods 4 with ANC, and AirPods Pro 3...
CarPlay Pinned Messages

iOS 26.2 Adds New CarPlay Setting

Thursday November 13, 2025 6:48 am PST by
iOS 26 extended pinned conversations in the Messages app to CarPlay, for quick access to your most frequent chats. However, some drivers may prefer the classic view with a list of individual conversations only, and Apple now lets users choose. Apple released the second beta of iOS 26.2 this week, and it introduces a new CarPlay setting for turning off pinned conversations in the Messages...
iPhone Pocket Short

iPhone Pocket Now Available to Order, But Already Selling Out

Friday November 14, 2025 6:20 am PST by
Apple recently teamed up with Japanese fashion brand ISSEY MIYAKE to create the iPhone Pocket, a limited-edition knitted accessory designed to carry an iPhone. iPhone Pocket is available to order on Apple's online store starting today, in the United States, France, China, Italy, Japan, Singapore, South Korea, and the United Kingdom. However, it is already completely sold out in the United...
tvOS 26 Profiles

tvOS 26.2 Adds a Useful New Feature to Your Apple TV

Friday November 14, 2025 10:02 am PST by
Starting with the upcoming tvOS 26.2 update, currently in beta, additional profiles created on the Apple TV no longer require their own Apple Account. In the Settings app on the Apple TV, under Profiles and Accounts, anyone can create a new profile by simply entering a name and indicating whether the profile is for a kid. The profile will be associated with the primary user's Apple Account,...
Tim Cook WWDC 2018

Report: Tim Cook to Step Down as Apple CEO 'as Soon as Next Year'

Saturday November 15, 2025 2:40 pm PST by
Apple is preparing for Tim Cook to step down as CEO of the company "as soon as next year," according to the Financial Times. The company's board of directors and senior executives "recently intensified preparations for Cook to hand over the reins," the report said. While the report said that Apple is unlikely to name a new CEO before its next earnings report in late January, it went on to ...
apple silicon mac lineup 2024 feature purple m5

Apple's 2026 Mac Plans

Friday November 14, 2025 3:23 pm PST by
Most of Apple's Macs are slated to get M5 chips across 2026, and there's a possibility we'll even see the first M6 chips toward the end of the year. Updates are planned for everything from the MacBook Air to the Mac Studio. MacBook Air (Early 2026) The MacBook Air will be one of the first Macs to get a 2026 refresh, with an update planned for the first few months of the year. The MacBook...
walmart new ornametns

Walmart Black Friday Deals Begin Today With Low Prices on Headphones, TVs, and More

Friday November 14, 2025 7:55 am PST by
Walmart's Black Friday sale has officially kicked off today, with an online shopping event that's also seeing some matching deals in retail locations. There are quite a few major discounts in this sale, including savings on headphones, TVs, and more. Note: MacRumors is an affiliate partner with Walmart. When you click a link and make a purchase, we may receive a small payment, which helps us...
best early black friday deals

Best Black Friday Apple Deals Live Now - Save on AirPods, iPads, and Apple Watches

Saturday November 15, 2025 1:45 pm PST by
We're officially in the month of Black Friday, which will take place on Friday, November 28 in 2025. As always, this will be the best time of the year to shop for great deals, including popular Apple products like AirPods, iPad, Apple Watch, and more. In this article, the majority of the discounts will be found on Amazon. Note: MacRumors is an affiliate partner with some of these vendors. When ...
iOS 26

iOS 26.2 Available Next Month With These 8 New Features

Tuesday November 11, 2025 9:48 am PST by
Apple released the first iOS 26.2 beta last week. The upcoming update includes a handful of new features and changes on the iPhone, including a new Liquid Glass slider for the Lock Screen's clock, offline lyrics in Apple Music, and more. In a recent press release, Apple confirmed that iOS 26.2 will be released to all users in December, but it did not provide a specific release date....
homepod mini thumb feature

New HomePod Mini, Apple TV, and AirTag Were Expected This Year — Where Are They?

Wednesday November 12, 2025 11:42 am PST by
While it was rumored that Apple planned to release new versions of the HomePod mini, Apple TV, and AirTag this year, it is no longer clear if that will still happen. Back in January, Bloomberg's Mark Gurman said Apple planned to release new HomePod mini and Apple TV models "toward the end of the year," while he at one point expected a new AirTag to launch "around the middle of 2025." Yet,...

Top Rated Comments

Black Magic Avatar
48 months ago

I'm still on iOS 14, but it looks like I need to upgrade since a policy at work requires I am on iOS 15 in order to use the internal Wi-Fi. I am going to try to hold out for iOS 15.5.1 though.
You holding out for what? You denying yourself great features thinking you are saving yourself from bugs and headaches? You like 2 years behind the curve and you feel like that is something to brag about?
Score: 9 Votes (Like | Disagree)
Y014951 Avatar
48 months ago

What features am I missing out on exactly that are so detrimental? I have been doing this every year since iOS 11. At the end of the day, it’s about the apps. iOS is just an OS. Most of what I already need in terms of integration doesn’t require iOS 15.
I honestly don't understand the downvotes. Mr. Dee seems to be a quite active participant in the Macrumors forums so I believe he knows what features he's missing. It's his decision to update his devices (or not) after all...
Score: 7 Votes (Like | Disagree)
Black Magic Avatar
48 months ago

What features am I missing out on exactly that are so detrimental? I have been doing this every year since iOS 11. At the end of the day, it’s about the apps. iOS is just an OS. Most of what I already need in terms of integration doesn’t require iOS 15.
Your employer is trying to nudge you into the present. You are obviously missing the point.
Score: 5 Votes (Like | Disagree)
now i see it Avatar
48 months ago
and good riddance
Score: 4 Votes (Like | Disagree)
canadianreader Avatar
48 months ago
We need the right to downgrade. I hope sideloading will open that door.
Score: 4 Votes (Like | Disagree)
Mr. Dee Avatar
48 months ago

Your employer is trying to nudge you into the present. You are obviously missing the point.
The same employer who has Windows 7 clients all over its network?
Score: 3 Votes (Like | Disagree)