How to accept Apple Music Family invite without iOS/macOS? A couple of days ago I upgraded my Apple Music subscription to family mainly so my sisters could access music from their iPhones. Since my dad is avid music listener I decided to set up Apple Music for him also on his Windows laptop.

I sent the invite via email and then we created an Apple ID for him with this same email address. But there seems to be no way how to accept this invite without owning Apple device or at least Android one. This seems odd since iTunes is basically the Apple Music for macOS/Windows.

In my family sharing settings I still see the invite as sent and when I open iTunes on his Windows machine there is no indication that there is Apple Music family invite.

Have I missed anything or is this simply impossible? 

EDIT: I found a solution. I created new user account on my Mac, signed in with dad's Apple ID and the Family Sharing invitation popped right up. iTunes on Windows now works fine.

Still would be nice to know if it is possible to accept invitation without Mac or spare iOS device..
No - you'll want to find a spare iOS device for your father's account to log in and accept the invitation. (or backup / wipe / set up your device for him - then wipe / restore your backup so that you don't mix streams of data signing out and then signing in as his account).

This would clearly be a bug and something you might be able to call Apple Support to see if they can push an alternate way to authenticate your father to the group.

My guess is the account is either blocked and needs apple push notification to tie it to a physical device one time and then it will work from windows. I've done this a handful of times for people that primarily are on Windows without needing to engage official support.