Overseas Travel: How can I avoid incoming call costs but still use free text/data roaming while abroad?

@tmo_chris Thank you so much for responding to my question with detailed info on how I can push calls directly to voicemail when traveling so I won't get billed for unwanted "spam" calls. I appreciate the information!

And thank you, @drnewcomb2​, for the additional suggestions.

Thanks again for the help!

   As I recall, you will get notice (free) that you had an incoming call.  I haven't used "fwd all calls to VM" in a few years since I don't mind spending the 20 cents/min.  Because of time diff - turn off phone at bed time - don't want texts in middle of nite..   (Also, still in habit of fwd. all calls to VM when I do that because you might be charged for incoming calls that get routed back to VM when not answered.)   Don't know if that's still the case.

I have the **21*18056377249#  and the ##21#  as speed dial numbers.

Another detail; the **21 and ##21# codes are called GSM Service Codes (or Hash Codes). Your phone may have a specific forward menu that will accomplish the forwarding commands without having to enter a yard-long Service Code. In the example above the ##21# code actually says "deactivate and forget". Rather than using ##21#, you could use #21#, which says "deactivate but remember". Then when you want to reactivate forwarding, you'd enter *21#, which says "reactivate". All of the assumes T-Mobile hasn't monkeyed with the "Forward All" commands. They changed the conditional forward system so that if you try to deactivate conditional forwarding it will reset itself to voicemail (And a pox on their house for doing it.) BTW, there should never be any charge for using these codes.

P.S. It's a good idea to practice using these features before you travel.

Thank you for your sharing your experiences and suggestions, @miket and @drnewcomb2​ -- I appreciate it!

Hoping this works as 1) I've had exponential increases throughout this year in robo / scammer calls - i.e. ~10 per day and 2) I'll be traveling internationally so don't want to be incorrectly charged for these scam / robo calls that realistically the mobile networks (read T-Mobile) should be working harder to block / stop in the first place - cc @tmo_mike​ - please share any articles or support as to what's being done on this front to preserve the T-Mobile customer experience and if anything additional can be done on this front from the user perspective.

As I (and others) stated above - our method has worked for years.   TM is the only carrier that lets you roam in most intl. countries w.o. spending lot$ of $.

   One more tip (which I don't use myself) - you can make use of the free data by routing voice calls over data services.  (Skype etc.)

I agree that we need a way to block unwanted calls while abroad and still let people we need to have call us get through. Unfortunately, the only way I've found to do this is to either have them text you first, so you can call them back, or give them a back door, such as a Viber or SIP address.

Simply Forward directly to VM ----      805-637-7243

Even now that TM has had "free" intl. roaming the past several years - still make sure at night time calls are forwarded to VM so as not to be awaken  by calls when it's still daytime at home.

Visual VM should do this but if you let calls roll over to voicemail you will be charged for the call. You can forward all calls to voicemail and listen to them via Visual VM

@tmo_chris - I am right now on a call with T-mobile customer care and they can not confirm that I will not be charged if I follow the steps you provided above. They are saying that I will still be charged as the call will be redirected and that will be a charge on my account.