Not sure if how the other people's setting, but I have Data Roaming enabled on my phone.

The message is for people who don't have an international roaming plan as some folks do not know that their data package is often domestic use only.

If you have the correct plan and don't get charged for roaming, then you won't get charged extra.

And if you don't turn the switch on, you will find data does not work when you're roaming.

Most folks don't have international data plan for their TMO sim card. I have the free 200 mb/month plan only and therefore turn data roaming off when abroad. I then either use wifi or piggyback off my 5s using BT hotspot.

Thank you for your replies. I've added this sentence to the wiki:
When using a T-Mo Simple Choice plan on an iPad internationally, you need to turn on Data Roaming on the iPad Settings.

Another thing I've been wondering about: I plan to use the iPad as a hotspot for a laptop. Will this tethering cause any problems with T-Mo? (E.g., cancel my account while I'm traveling?)

I've tethered.

Very slow but it kind of works.

It dawned upon me when reading your post that if you don't have an international roaming plan, even if you don't turn off roaming, I don't think anything will happen. In other words, at least with my free 200 mb/month plan, I CAN'T use outside of US unless I specifically add supplemental plan. I'll double check next time I speak with TMO CS.


Correct, most times incredibly slow. I use it primarily to download emails that require longer reply. Not recommended for extensive internet surfing, LOL!

Does the slowness during tethering appear to be related to the slow data link between cell tower and tablet, or something happening (slowly) within the tablet related to its tethering software?

It can be slow when you're not tethered.

The bottleneck is that they throttle it, not the Wifi link between the tethering device and the sharing device.

What if you are in a country that isn't on the free list?

I'm pretty sure I tethered my iPad (no cell) to my wife's iPhone on our last trip to Mexico. No charges and no problems. Can't remember 100% though if that's exactly what I was doing.

Good point FreakingFlyer! I've updated the wiki sentence.

You need to turn on data roaming in order to use data while roaming, regardless of which non-US country you're in, whether or not you have a Choice plan that gives free data in 120+ countries, and whether or not you're in one of those 120+ free roaming countries.

When you first enter each country, T-Mobile will send you an SMS that tells you what the roaming charges are for that country, based on the country and your plan at home. If it's not one of the 120+ "free" roaming countries, or you don't have a Choice plan, then it will tell you what the data roaming rate is, as well as a code that you need to enter in order to enable data roaming. So, I don't think it's possible to use data roaming that will result in a charge, unless you specifically enter the enabling code, regardless of the setting on the phone.

You simply dial #763# when you want to block roaming charges... then re-enter if you want to turn them back on. Toggle as needed when traveling.

Anyone have experience with using google maps with t-mobiles global coverage in mainland Europe (Netherlands, Germany, Switzerland, Austria)? Too slow, should I get a local GPS, etc...will be using it on an iPhone 5.

It works, the first time you load an area which was never cached before can take a long time though.

I used it for a train ride from Amsterdam to Paris and I didn't pre-cache the map before I left so it was using the slow connection all the way.

It drew the map at a high level. If I tried to zoom in on any area for detail, it took awhile to download that portion. So that means it displayed the outlines of the area but not borders or city labels unless I zoomed in and gave it a chance to download more data.

I've found it perfectly acceptable in various parts of Germany, Belgium, France and the Netherlands. I'm currently in Amsterdam and (so far) it's very good indeed.

Map retrieval can be slow on trains travelling at high speeds, as wco81 says, but that's obviously a fairly demanding use (and typically not essential: train drivers tend not to need your help finding their way ;) ). It is certainly almost always good enough for driving, walking or using local public transport (to find the nearest bus or tram stop, for example, or to check that your taxi driver is taking a sensible route).