It's not fraud. For some reason UPS calls for every package if it crosses the border. So I had ordered something from Amazon and had received it this morning. They called to ask if I would give permission to let it clear through UPS.

Legit, its UPS. They provided a reference number in the message, not the same as the tracking number but if you go to UPS site and search by reference it will point to your package. They did not want money, just wanted auth to act as broker for the package.

Yes they are UPS.  We have gotten packages from USA New York and they even said the name of the place. I guess every once in a while they like to make sure,  & she even told me there was a charge with it.
Nice, kind women.

It's legit. UPS.

It would appear to be a valid number from UPS.  That said, instead of calling this number, since I could back trace it, I simply called their 1-800 number (1-800-PICK-UPS (1-800-742-5877) - pulled from their website) and the operator had absolutely no problem dealing with the issue (brokerage).

It's a UPS number.
Enter the reference # from the message into the "track by reference" field on UPS' website.

Got a call from this number earlier this month. I was away from the phone at the time, so they left a message saying that it was UPS. I didn't ever call them back, despite the fact that I was waiting for a package through them, but I still got the package (actually got it sooner than I thought I was going to get it).

It's an absolutely legitimate number. Got the call and I thought the automated message was weird too so I googled it, read the comments here, and checked out the tracking number they gave me. But everyone else is right - put it in as a REFERENCE number. Came up with what my mom shipped from Germany, so she called the number, they asked for the tracking number, and asked how we wanted to get it cleared through customs, etc. So. It's definitely legitimate.

855-210-3500 is a legit UPS number for package clearance from the USA. I deal with them all the time re: y business.

Thanks for your reply, I searched by reference number and it was in fact an actual shipment that we were expecting. It seems odd that you get an automated call telling you to call, but I guess that's how they do things now. I'm glad it isn't spam as recently I've been getting a lot of email spam saying a package has arrived.

This number really is legitimately UPS, it's not a scam. I ordered something online from a US store, 2 days later I got an automated number with a message saying it was UPS and they had a package that needed to clear customs (not a coincidence) and gave me a tracking number. The message said the package was for my fiance (his name is in no way connected to any of my accounts or my phone number, but I put his name down as the addressee when I made my online purchase, that's the only way any one could have gotten his name). I called back the next day, got someone from UPS, gave them my tracking number and sorted everything out. They were able to use the tracking number and tell me that my package should be delivered the next day, but when I tried the same number on the UPS website (both Canadian and US) it didn't work. UPS probably just has a different tracking system that they use for customs vs. regular tracking by customers.

You can track using either number as explained here by UPS  http://www.ups.com/content/ca/en/resources/track/check/index.html  
I suggest using the Tracking Number because this number is ASSIGNED by UPS and not by the shipper and less possible to fake.
I could not find 855-210-3500 (or any other number) on the UPS website. UPS has been in business for many, many years. It's kind of strange that 855-210-3500 suddenly sprang up as a new number for UPS Customs Brokerage so BEWARE if this number asks you to send it money or personal info. If 855-210-3500 calls you, do not give personal info or money.

Yann is absolutely right, track it by REFERENCE #..I needed this post to instruct UPS how to go about it!!!

It's not a fraud.
When you track it, track it by REFERENCE #, not tracking#

Recived an automatic message from UPS. Since I don't have any package waiting to be cleared, I didn't returned the call.
Why are they choosing an automatic voice mail, instead of a human???? Sounds wird to me.

I actually called UPS (Not the number that is provided in the automated call, but 1-800-742-5877 which provided in their website).
It turns out it wasn't a spam. As weird as that tracking number looked it was real.

automated call apparently from UPS. Told me I have a package at customs, and should call them to give them permission to clear it. The tracking number was weird. I'm pretty sure it is some sort of spam.

Received a call from the same number.  While the tracking number doesn't work online, it is in fact UPS.  The tracking number on the phone led them to a legitimate purchase I made that was shipped VIA UPS.

It's the UPS brokerage clearing number!

this is the fraud number for sure.

Yes, I had received a call from this number, said that they were UPS and gave me a tracing number. Tried to track it online and it came up unknown. Called the number, UPS answered, gave them the tracking number and it was about the shipment from the US into Canada, Brokerage. Nothing bad here.

RECEIVED A CALL AND TRACKING NUMBER DID NOT EXIST.

Got a call informing me to call the above number to clear a package through customs
Tracking # E13407VGK4Q

Checked on UPS site....tracking # does not exist

This is UPS Brokerage clearance into Canada.

Called me last night.