iMac turns iPhone Personal Hotspot on

Will_M · April 7, 2019, 9:38pm

I have an iMac (I believe it’s a 27 inch Retina display) that I use infrequently. I have an iPhone SE with a data plan. Today, the iPhone’s Personal Hotspot was turned off and I used the iMac.

I was surprised to see that the iMac offered, under the Wi-Fi menu, to connect to the iPhone. I confirmed that the Personal Hotspot was off, and told the iMac to connect. It did, and the iPhone dutifully reported one connection. It also showed the Personal Hotspot was on. I turned off the Personal Hotspot and again told the iMac to connect. It did, and again the Personal Hotspot was on.

This strikes me as extremely odd, and troubling. Why would the iMac be able to detect the iPhone if the Personal Hotspot is off, and why would the iPhone turn the Personal Hotspot on in response to the iMac? At most, I would expect the iMac to whine about the Personal Hotspot being off and the iPhone letting me know something wanted to connect, but I absolutely believe that if I turn off Personal Hotspot on the iPhone, it should stay off (until I turn it on, on the iPhone).

While I don’t doubt that I did, at one time, use the iMac to connect to Wi-Fi on the iPhone, I don’t recall doing so. However, I have used a MacBook to connect to Wi-Fi on the iPhone, and the MacBook does not show the iPhone in its Wi-Fi menu when Personal Hotspot is off.

Any ideas what is going on?

allen.gainsford · April 7, 2019, 9:54pm

If you look in the “Personal Hotspot” settings page, you’ll find a statement near the top that “Other devices signed into your iCloud account will be able to use personal hotspot without having to turn it on automatically.” In other words,
your other devices, if signed in properly, can turn your phone’s hotspot on automatically. It’s a convenience thing.

ddmiller · April 7, 2019, 9:56pm

This is something called “Instant Hotspot”. Your MacOS and iOS devices logged in to the same Apple ID can connect without turning on personal hotspot first. See:

alvarnell · April 8, 2019, 12:07am

Yes, it’s a new feature that came with iOS 12.

Will_M · April 8, 2019, 3:13pm

Thanks for the replies. I learned something new, and it’s nice to know that the iPhone isn’t malfunctioning. Still, I would prefer to be able to disable this.

One remaining item of confusion is the MacBook. Certainly it is signed into my iCloud account, but it does not show the iPhone in the Wi-Fi menu, like the iMac does. This is inconsistent with the descriptions of why the iMac (which is also signed into my iCloud account, and I just confirmed that they are both signed into the same account) was able to enable and connect to the iPhone. Thoughts?

ddmiller · April 8, 2019, 3:52pm

In addition to a minimum macOS version requirement, there is a minimum system hardware requirement (that I believe has to do with the version of Bluetooth that is supported; Instant Hotspot is a handoff/continuity feature.) It may be that your MacBook is too old?

See https://support.apple.com/en-us/HT204689 for the minimum Mac system requirements. See the section under “Instant Hotspot”.

Will_M · April 8, 2019, 4:36pm

Thanks for the follow up. I don’t believe that’s it. The MacBook is newer than the iMac; About This Mac describes it as “MacBook (Retina, 12-inch, Early 2015)”, which appears to satisfy the hardware requirement. Both the iMac and the MacBook are running MacOS 10.11.6.

dianed143 · April 8, 2019, 4:49pm

I have an early 2015 MBP Retina and have been happily using the hotspot through my iPhone SE while at a client who can’t find their wifi password.

I haven’t tried it on any other machines.

Diane

Will_M · April 9, 2019, 1:30am

As I said, I have used the MacBook with the iPhone SE hotspot. What I have not seen is the iPhone SE hotspot in the Wi-Fi menu if Personal Hotspot is not already turned on in the iPhone’s settings. That’s the difference between the iMac and the MacBook.

ddmiller · April 9, 2019, 1:52am

Is Bluetooth turned on on the MacBook?

I suppose the other thing (if that’s not it) is to sign out and back in to iCloud on the MacBook.

dianed143 · April 9, 2019, 1:53am

Personal Hotspot is turned off on my iPhone, and I do see it in the wifi menu. (not trying to be argumentative)

Diane

Will_M · April 9, 2019, 12:28pm

Probably I’ll do that, so the Macintosh computers will be consistent. But the goal I would like to achieve is to disable Personal Hotspot when it is turned off.

I didn’t think you were, and you confirmed that your MacBook Pro is like my iMac (but both are different from my MacBook).

dianed143 · April 9, 2019, 1:03pm

Will, I’m glad you sent this now. I just checked my 2012 iMac (running Sierra like my MBP) and the phone does NOT show up in the list.

I never look in wifi since I hardwired it, so I never noticed.

It’s still showing up on the MBP though I am not connected to it. I wonder if that has anything to do with it.

Diane

mpainesyd · April 15, 2020, 6:47am

Update for 2020:
Not sure if it was in a recent iOS update but the Hotspot function has changed again. Now there is no longer an option to turn it off if devices logged into your iCloud account want to connect. See the snapshot of the new page in Settings/Hotspot.

While I can understand the convenience, it concerns me that I could end up using mobile data without realising it.

Simon · April 15, 2020, 2:51pm

I understand that concern, but I can tell you I haven’t encountered this with my Macs and iPhone yet. On my Macs I have to select my iPhone manually in the wifi menu to get them to tether off the phone. And on my main MBP I do this sometimes. As long as you make sure that the iPhone isn’t set as the default wifi for your Mac you should be ok.

But yeah, there should be a hard off button. Convenience is nice, but lack of control sucks.