This number just called and when I answered there was nobody on the other end - just silence for a few seconds. I hung up.
Seeing this thread, its seems to be T-Mobile. I just ordered new service last week with them.

received a call from 877-335 9581 answered but no one there.I also have t mobile

I too recently switched to tmobile. I got a call from this number while at work so I was unable to answer. Even if I was able to I wouldn't have because I simply don't answer numbers I don't recognize. No voicemail was left for me. There have been a lot of phone scams going on in my area recently so I do not feel comfortable with giving ANY info to an incoming call. (You'd be amazed with what someone can do with just an email.) Even if it is legit everything was confirmed when I activated my phone and I do not need a silly "welcome packet" when I already received at least 2 welcome emails and 3 welcome texts. Thanks but no thanks.

I've been a T-Mo customer for a LONG time. Why on earth would they send me a "welcome" call now? If someone out there legit works for TMo and makes calls from this number, please inform your employers that either your welcome call is fishy as hell, the autodialer is broken and is calling longtime customers, or someone unsavory is spoofing the number.

i blocked the the number on mr Number app

got a call after switching to t-moblie

i just used Mr. number app and blocked that call

Recently switched to TMobile.. Am I going to get a frigging call from someone -every time I contact customer service...HOLY crap STOP or I will switch to everyone who is now following your lead. Remember, I have NO CONTRACT...dont screw it up T-Mobile

We just switched to T-Mobile and hubby has been getting calls from 877-335-9581, he has not answered it, after looking it up on here I called T-Mobile and the rep was very nice and said it was not one of their numbers and that it was a scam, she escalated this issue to her supervisor for more research, in the meantime she said we could reject any number by first adding it to our contacts list, then going to the list and pressing on that listing until a prompt comes up that will allow us to reject it, that way it will automatically go to VM and this is at no charge, she said not all phones have this feature but all the newer ones do, another option at $4.99 a month will allow you to block numbers and does other things as well, can't recall all she said on that and the last option is to change your number which is not an option for us as we have had this # since 2006 and who is to say they won't get the new number. Good luck with this, just remember it is a scam so do not give them any information.

T-Mobile clearly tells people NEVER to give out personal information to anyone saying they are from T-Mobile, that they will never ask for your address or other info.  Verizon also warns customers against It, I fell for a similar thing when I had Verizon.

Received a call from this number, did not answer and left no message and after reading these comments it is now on my block list.

I signed up with T-Mobile a couple weeks ago, got a call from this number just now....but since their coverage is so crappy where I live, the call dropped right after she said "Hello..." lol!

They keep calling, no message

That sounds like an aweful lot of guessing and jumping to conclusions. For all you know they could have just gotten hacked like all the other companies in America to get our phone numbers (I also received a call). This happens all the time and it used to happen a lot more with emails too. You are acting like T-moblie is out to get you when really, this happens all the time in all different mediums. Is Target out to get you too since their card machine was hacked? I just switched to T-mobile too and I used to get more calls like this on Verizon, it doesn't mean it is Verizon's fault.

I also received a call from this number but it came at a time I was on another call so it went unanswered.  It is POSSIBLE that it's T Mobile because I recently purchased a phone from them and opened an account.  It could also be that someone inside T Mobile is assisting some scammer.  I would NEVER give any personal information to a call I did not initiate so if it IS T Mobile it's a very bad business practice on their part.

Just had this happen to me.  I called t mobile and they don't know about this number.  The rep even put me on hold and called it herself.
She said she thinks it may be an out sourced number but isn't sure.
It's being forwarded to their investigation dept. They said they would call me back if they needed any more info.

Hopefully they figure this out.

Just got T-Mobile. Friendly customer service isn't a phone call on a holiday weekend Saturday at 9 AM. F***. Off. I don't need to be welcomed. I pay my bill, so that's all you need.

It is tmobile. I, like everyone else, don't answer calls from numbers I don't know,  but accidentally answered this one.  He was calling to welcome me to tmobile.  I had signed up for service online days earlier and had just received my phone the afternoon before.  After he verified my info, he said they were the welcome center and wanted to know how everything was going with my phone.  I explained that I ordered a plan with unlimited data,  and although my phone was allowing me to access the web, one of the notifications in my notification bar indicated that I hadn't signed up for a plan with data.  He apologized for the inconvenience, did whatever he did on his end,  then told me it was corrected.  I received a notice from tmobile via email saying changes to my account had been made,  and the notification disappeared.  He said he noted it in my account so I would not be charged extra for the data I used when the plan was set up incorrectly. I was then transferred to a customer survey for tmobile.  I called tmobile back a few days later for a question about removing preloaded apps from my phone,  and asked them about that note to ensure I wouldn't be charged,  and they ensued it was there. After the v call I was transferred to the same tmobile customer service b survey I took days v earlier after the first call from this number.

It is officially t-mobile. I signed up for service a few weeks ago and it was them calling to welcome me. They went over my bill and everything - after I called them back.

If the guy on this thread is really form T-Mobile, how come the phone number he provided is NOT their normal customer service number?

I did call T-Mobile from my phone.

I just signed up with T-Mobile. I did not answer this call since I did not recognize this number. I called T-Mobile about a billing question and asked her about the number based on these posts. She told me they will NEVER call me for anything other than if I have a problem with my account (like not paying my bill). She said they do not call and welcome you.

Maybe the couple of replies that deny this are the scammers themselves. I did not come on here and type my job's phone number to see what people said about it. Why did you?

It was T-Mobile calling to confirm that I had signed up for their cell phon service and asking if I had any questions about my account. I was not asked for any personal information.

how i stop this  this is  can some body help me

The calls are not from T-Mobile.  I verified this with T-Mobile.  I refused to give out any information as T-Mobile would have it.  Especially my number. Calls began immediatley after my service began.

Ditto here. New T-Mobile customer, DID NOT ANSWER because it doesn't say "T-Mobile" when they are calling. I don't answer unknown calls. They did not leave a message, and should have. And that "Calling programs can't do that" excuse... Ummm... I get spam every day from calling programs that leave sales pitches for their product or services. The technology does exist, lol.

Take a clue, T-Mobile, don't use an anonymous # and expect people to answer. (rolls eyes)

I tried to call this number back and verified that this is from t-mobile welcome center. It is not the customer service. You don't need to answer the phone. it is a courtesy call.

After receiving a call from this number with no one answering, I called it back.  It is from T-Mobile (automatic dialing system).  It is a "curtosy" call from them asking how their service is.  I did tell them that it would be nice if the automated service would leave a message.  But was told that can't happen with an automated dialing program.

got this call today saying from t-mobile to welcome me called t-mobile back and they said it is from their welcome center.

When a stranger calls me, I GIVE OUT *NOTHING* *NOTHING* *NOTHING* *NOTHING* *NOTHING* *NOTHING*

You spew NONSENSE !!!
Re. "we already have your information in front of us we just have to confirm your address and email", when a stranger calls me, I do NOT have to confirm ANYTHING, the *STRANGER* has to confirm him/herself to *ME* and not the other way around.
Folks, do NOT call this number back, always call the regular T-Mobile customer service number.