I have been a fan of Apple (both design and engineering) since I bought my first iPhone. However, far from what Steve Jobs might have wanted, Apple products, including the iPhone has limitations. While Apple is said to “take the best decision for the user”, the fact that you can’t change much on an iPhone (unless you jailbreak it), it sometimes a pain.

One of the shortcomings of iOS (compared to Android) is to use the Mobile Data (3G/4G) to update its own software. I am not sure why the OS insists me to have a WiFi connection while more than 200 GB data sits in my account with my carrier. While I was able to work from home and enjoy Netflix and Hotstar and download VMs and whatnot, the one thing that gave me a headache during the lockdown was the inability to download OS updates using Mobile Data.

The funny (actually, annoying) part is - if you have two iPhones and you want to use the first one as the hotspot and download the update on another - Apple still does not allow that.

However, there is a way out; in fact, there are two ways out of this.

Download the update on your Mac

This method is the simpler one. You can plug your iPhone to the Mac. The phone shows up in Finder (Catalina and above) or iTunes (macOS versions before Catalina). You will get the option to download an update the new OS release in the general tab. Of course you can use the iPhone’s USB tethering itself to download the update - so that problem is solved!

This method however would download the full update which is way larger than the over-the-air update which iPhone usually downloads. The full update installs on the phone faster but needs that the phone be connected to the mac for the whole process. I am scared to find out what happens if you pull the device out of USB port while the update is happening but I am assuming it could brick the device.

However, if you don’t unplug the phone from mac while it is updating, this does the trick!

Use USB internet sharing

Downloading the full update costs mobile data and here in India, most users get a “Daily Limit” on data, typically between 1 and 1.5 GB of it, every day. Once you have consumed that much in a day, the speed reduces to a crippling 64 Kbps. For an update that is between 4-8 GB, that would mean you would have to keep downloading it for days (and not use the mobile data for anything else).

My brother had the daily limit plan while I had more than 200 GBs of data from the past months unused data roll-overs. While looking into the System Prferences, I found a gem of a setting which I then used to update his iPhone using my mobile data (remember that iPhone to iPhone hotspots are not allowed by Apple for iOS updates).

{% include figure image_path=“/assets/images/internet-sharing-on-mac-for-iphone.png” alt=“System Preference for sharing Mac WiFi connection to iPhone via USB” caption=“System Preference for sharing Mac WiFi connection to iPhone via USB” %}

  1. Within System Preferences Sharing, you have a setting which says “Internet Sharing”.
  2. I set it to Share your internet connection from WiFi to devices using iPhone USB (if you have an iPad, also enable the sharing for “iPad USB” connection).
  3. Connect the Mac to my iPhone’s WiFi hotspot and connect my brother’s iPhone using the USB.
  4. Disable Mobile Data and WiFi on my brother’s iPhone and test if the internet works. I could see that only one of the USB ports on my mac was sharing the internet connection even when both USB ports were working properly.
  5. Start the update process on my brother’s iPhone.

The second one is more of a bandaid than a clean solution, but if you have a Mac, and want to use someone else’s iPhone’s Mobile Data for updating your own iPhone’s iOS version, this is the only trick that I know that can work.

I hope and wish Apple enables OTA updates soon for iPhone. Till then, this should serve you well.