Google Hangouts, Google Voice, International SMS, and Tmobile

My goodness, this was difficult to find...So here's the deal. Google Hangouts has always been my default sms app because I have a Nexus 5. But I also had a Google Voice number because I wanted a permanent way for people to contact me. The way it worked was that if someone sent me a sms, I could choose to see the sms in my gVoice app or in Hangouts. If I chose gVoice app and responded using my gVoice app, my contacts would see my gVoice #. But if I responded using the gHangouts app, they'd see my "regular" mobile number (not to mention the terrible way this system assigned pseudo numbers to contacts!). This made things really cumbersome. What I wanted to see was that no matter where I sent my SMS from, people would only see one and the same number-- my gVoice number.

So in September, when they rolled out better integration between gVoice and gHangouts, I was thrilled. Now when someone sent me a sms to my gVoice number, I'd see it in Hangouts. Plus if I replied to them in gHangouts, they'd see my gVoice number. If people sent me a SMS to my regular mobile number, I could still reply using gVoice number! In other words, finally one number to rule them all!!!

But not so fast....the integration left some unanswered questions:

1. Does sending SMS from Google Hangouts use my texting plan or my data plan? And how much does it cost?
2. Can I send an international SMS through Google Hangouts once it had been integrated with Google Voice?
3. How much does it cost to send an international SMS?

After much looking around, it seems that sending SMS from Hangouts will utilize your carrier's SMS plan and rates. See the forum response and Google's help site:

If you have the Hangouts app on devices with Android 4.0 and higher, you can send and receive text messages (SMS & MMS), photos, and videos. Remember, your text message rates through your mobile carrier still apply.

Ok, so it uses my texting plan. Since my carrier is Tmobile and I'm using their $30 ("Walmart") plan, I went back to Tmobile to see what the plan entailed. The $30 plan includes:

• 5GB up to 4G speed 
• Unlimited Domestic and International Messaging
• 100 nationwide minutes ($0.10/minute for additional voice minutes)

Wow, so my carrier rates for SMS is $0! And look, it seems that Tmobile also gives me unlimited messaging to international numbers! I called and double checked to make sure that the plan did include unlimited international text messaging! Could that really be? Yes! The post and the call both confirmed that international sms were free!

I should point out this type of unlimited international text messaging is NOT the same as having an international plan. For this feature international txt messages must originate in the U.S. In contrast, an "international plan" would allow you to roam and use your phone while you're in other countries. There doesn't seem to be any charge for receiving international text messages. According to their website:

Unlike our competitors, there’s no need to purchase an expensive international plan—it’s now automatically included with our Simple Choice Plan. 

Truly unlimited texting: T-Mobile is the only US wireless carrier to deliver unlimited international data and texting from 120+ countries and destinations, PLUS we’re now adding international texting from the U.S to virtually anywhere*– all at no extra charge. 

The world is your network: Simple Choice customers can enjoy unlimited data, texting at no extra charge, and flat-rate calls for just 20 cents a minute, while traveling in 120+ countries and destinations—and growing."

Summary so far: 

• Sending SMS from Google Hangouts utilizes SMS rates from carrier,  
• my carrier (Tmobile) gives me UNLIMITED SMS to US, and
• my carrier (Tmobile) also gives unlimited SMS to most international numbers

So far, so good. Now what about those international SMS? Well here's where I hit a snag. Although my carrier doesn't charge me fees for sending and receiving international SMS, Google discontinued support for sending international SMS a few years ago in gVoice. So even if my carrier does not charge for international SMS, I am not able to send international SMS using gVoice. Moreover, if my gVoice was my chosen number to use in gHangouts (see the one number to rule them all comment above), then I wouldn't be able to send international SMS in gHangouts using gVoice. And that's exactly what I discovered. If I switched to another SMS client (which usually only allows you to use your mobile phone number), I could send international SMS without a problem (because it would go through Tmobile). If I switched back to gHangouts and tried to send an international SMS, then the message wouldn't go through (because my gHangouts was configured to use gVoice). 

The only way to fix it was to configure gHangouts to use either gVoice or regular mobile number in different circumstances. Open the gHangouts app, go to Settings -> SMS and choose the Smart Reply feature. Now I send international SMS using my regular mobile number (routed through my carrier) and domestic SMS using my gVoice number. Unfortunately, this means that my dream of one number to rule them all is gone. International contacts see  my regular mobile number and domestic contacts see my gVoice number. Still since either way, it's free... I can hardly complain!