I have Mobile One service which includes international services while traveling. When traveling internationally, will my phone automatically connect to only T-Mobile partner carriers? Will the phone not connect to non-partner carriers unless I override or manually select a carrier? Is there some sort of carrier management in place? Sometimes, I get a SMS/Text which confirms that my T-Mobile service will work - other times, I get nothing. I'm not able to find a list of partner carriers on the T-Mobile website. Any advice would be appreciated. Thanks!
Best answer by Anonymous
Your key is the coverage map. If it's shown on the coverage map, it's supposed to be covered. If not, well best of luck. T-Mobile doesn't generally publish lists of roaming partners and it's possible that you may find different roaming arrangements in different areas within a given country. This is particularly true in India, where it seems that roaming agreements are negotiated on a state-by-state basis. T-Mobile is also capable of using LAC-blocking to control which carriers customers can roam in one area vs another.