Calling this number can be useful if you're looking for assistance with United Airlines account. However, it appears that you need to have an established account with United Airlines to use this service.
When I called, I was told that my number was recognized and the system wanted to confirm who was calling. I confirmed that my number was attached to my name, and the system asked if I wanted to have it automatically tie my number to my United Airlines account moving forward. I said no, and the system confirmed it would continue to ask me to confirm my number.
The system then asked if I wanted to continue the conversation via text messages instead of on the phone. It said it would text my number if I wished, with standard messaging rates applying. I rejected that suggestion and instead asked if I could check my miles balance.
Next, the automated voice had me verify my personal information, including my name and the zip code attached to my account. I could have also provided the number for my United Airlines mileage account, but as I didn't know it, I opted not to. Upon checking and confirming my miles balance, the system asked if I had any other questions that it could help with.
I asked it if I could check my transactions with United, and it said it could check recent transactions, but anything older than 6 months ago wouldn't appear in the system. Instead, I'd need to contact United through e-mail to get access to those records. As I only wanted to check the most recent transaction, I opted to end the call at this point.
Overall, this was a fairly good experience, although the need to have a United Airlines account and have it checked can make it restrictive. On one hand, it's a good thing that the company does so many checks to make sure that you're who you say you are when you're traveling with them. On the other, it does seem a bit excessive to have this many checks in place when all you want to do is check your mileage account and whether you're closing in on a vacation.
Whether or not I'd recommend using this number depends on how extensive your issue is and whether you can solve it without a one-on-one interaction with someone. If you only need basic assistance, the system does a good job providing it. If not, you'll be better off trying another number. Also of note: be careful when dialing this number to avoid mistakes, as missing by one number can send the caller to United Healthcare instead of United Airlines, which was my own experience the first time I dialed.