I thought the same. But last month after I canceled two rewarded tickets, the miles didn't get redeposited. It showed up as a future credit and I had to call the agent to refund it to me.
The two rewarded tickets were changed several times before I canceled though.

Is it common for United to show phantom space on their own metal? EWR to SFO flight is showing IN space but erroring out when I am trying to book. Called agent and she sees it too but then transferred to supervisor and they said space isn't available on the 8:15am flight even though it's showing as available but she did mention the 6:15am is available.

Award travel redeposit fees
 

I thought I’d read that there is a fee to redeposit for travel from Europe, Asia etc to US, no? On United metal.

UA has recently updated the award fee chart to remove cancellation / redeposit fees worldwide

Prior to that, while ex-USA had not fees, UA could have changed a fee for other award tickets but had issued a waiver on these fees. So there have not been fees for some time in reality.

Are mileage tickets refundable? Can I use my mileage to buy a ticket for my wife?
 

My wife Might want to travel 3 months from now. I think mileage tickets are refundable, so that would be my preference.
My wife doesn't have enough, but I do. Can I book a ticket for her with my miles?
Thanks for your help. The info on United.com is so confusing...

Yes on both counts. If she chooses not to fly, you need to cancel the ticket prior to departure to avoid a $125 no-show fee.

I book flights via my mileage plus account on frequent basis for my wife and my daughters. Just make sure to set up her profile as the passenger instead of you as the default which I have screwed up a time or two when I was in a hurry or not concentrating.

And just to confirm: Partner awards can be canceled online for international departures as well? Trying to determine if I will need to call UA while abroad at the airport.

In theory, yes, but be prepared to call, as the online tool occasionally fails.

Not sure if this is new to the community, but the removal of award fees opens up a loophole that was really only available to 1Ks/GS.
You know how UA raised the cost of *A award bookings and changed their close in booking fee from $ to essentially a mileage surcharge? Well the way I’ve found to avoid both of those is to book a multi-city itinerary. The first flight will price out as you’d expect with extra cost, but the second flight will be old award chart pricing. Book the itinerary then cancel the first flight. Easy peasy.
It used to be this maneuver would cost a change/cancel fee for platinum and below, but I guess not anymore.

UA should be recalculating the price, but I guess I’m not shocked if they’re not. However, if the second leg is a partner leg — which it sounds like it is in this situation — it’s possible that the change will error out if there’s not additional inventory on the target flight.

That has not been the case in the times that I’ve done this (I've only ever done this with ANA, EVA, Thai, and Asiana, but so far it’s been 100% success rate). Again, there is no barrier to testing this out now so if you’re skeptical, I’d encourage you to try it for yourself. The worst that could happen is you cancel the entire itinerary and get all your miles back, best case, you save 10%+ on your next *A award.

Might be a simple question, but does anyone know if you can cancel a booking containing a confirmed MileagePlus J upgrade? Hoping to get my miles/co-pay refunded as well as the original fare back as United credit. I saw some conflicting reports while searching so I'm not sure.

Cancel the entire booking, yes and the upgrade miles and fees will be refunded.
Canceling just the upgrade, that gets trickier and in some corner cases can not be done (or only done at the airport).

Oh gotcha, thanks for the tip. Could I cancel the booking online or do I have to call in for them to trigger the miles re-deposit?