Update to WatchOS 10 instead to WatchOS 11

[Jack Napier X]

Hello, I hope somebody knows how to do this.
I have an iPhone that I do not wish to update to iOS 18 yet. I also have an older Watch that I'd like to update to WatchOS 10, as it is currently on WatchOS 9.
Unfortunately, my iPhone quits the updates process by saying that I have to update my phone first even though it is on 17.7 which is still signed by apple. I don't get it. So you can only the update the watch if you're on iOS18??? Or is there a way to manually force the watch update to OS10?

 

[Shirasaki]

Short answer is you can’t.
Apple will not sign an Install of any operating system (modern one that is, which watchOS 10 is) unless there are exceptional circumstances or that’s the last supported version of the device.
This means, if your device is not supported by iOS 18, but your watch can support watchOS 11, you are out of luck.
You can try to contact Apple support but I am fairly confident they will just advise you to upgrade your iPhone.

Now, if budget is no constraint and there are plenty of tools, one might flash watchOS 10 outside of Apple Watch itself and try to see if it will work. It’s out of scope for most people but technically it might work.

 

[Jack Napier X]

And which tools would that be?

 

[kofman13]

i am in the same boat.
I had iphone 13 pro running ios 16 and apple watch 6 running watchos 9. the other day i updated my phone to ios 17.7. now the watch doesnt work with the phone anymore and it says "updated required" on the watch and then says "your phone must be updated to connect to apple watch" meaning i need to install ios 18 just to use my phone. i had ios 16 and watchos 9. why didnt updating to ios 17 make the watch go to watchos 10 and just work?

 

[Shirasaki]

And which tools would that be?

All the fancy soldering, desoldering tools electronics engineers likes to use, and/or those tools that manufacture those phone motherboards etc, tools to flash memory chips onto Apple Watch motherboard and more. You won’t have access to those tools (easily) and even if you do, it’s a huge gamble as to whether it will work or not. Worse off, Apple can still deny the activation of watchOS 10 anyways.
Basically, don’t bother. Either upgrade your iPhone or try to find a watch that is running watchOS 10 and never upgrade it.