Using a dual Sim mobile phone correctly overseas

[Asiantravel]

I wondered if some one might be so kind as to clarify the use of a dual Sim mobile phone.

 

My SIM 1 slot has my True Move Sim card for use within Thailand but I have never before needed to use the second slot for Sim number two.so I never before realised how much there is involved in using both slots simultaneouslywhen you're travelling (if you’re like me and not familiar with these things).

 

At the end of this year I am travelling to Japan, USA, Mexico and Peru. True Move have already confirmed that I will be able to keep using my Thai mobile number everywhere except in Peru.

 

But regarding the phone handset itself I have been advised that my phone is Dual/Multi-band which can use both of the standard GSM bands used globally. It also has support for 3G/HSDPA 900/2100MHz - GPRS/EDGE which I am told is the higher level of connection but that this is usually supported only by the primary SIM (which I assume is Sim number 1) on dual Sim devices.

My main concern has been the time I spend in the USA because whenever I visited during the 1990’s they always seemed to be on different standards completely to the rest of the world regarding telecommunication technology.

 

My question is if I use the SIM 1 slot temporarily for prepaid SIM’s I will buy in Japan, USA and Mexico to allow for the different standards,  will the TRUE MOVE Sim with the Thai number keep working okay in the SIM #2 slot?

Edited July 19, 2017 by Asiantravel

[thecolonel]

All I can report is that I have had no issues as re sim 1 sim 2 I have UK in sim 1 and Thai sim 2 see attached...mostly I turn off Thai when in UK and vice versa, I turn on when I need to or to check. My phone is cubot note S and does not support 4g. But I have only travelled in thai and UK not used in other countries, oh that said I'm fairly sure I used thai sim in Cambodia, but then replaced with a local. Not being funny but what is your real concern here? You can always put a local sim in...

Sent from my CUBOT_NOTE_S using Tapatalk

[thecolonel]

Ps just re read... it will depend on your device, my tru move works in slot 2 and outside of Thailand /UK but maybe that's because my device enables that but it was only £70!!!

Sent from my CUBOT_NOTE_S using Tapatalk

[Asiantravel]

2 hours ago, thecolonel said:

All I can report is that I have had no issues as re sim 1 sim 2 I have UK in sim 1 and Thai sim 2 see attached...mostly I turn off Thai when in UK and vice versa, I turn on when I need to or to check. My phone is cubot note S and does not support 4g. But I have only travelled in thai and UK not used in other countries, oh that said I'm fairly sure I used thai sim in Cambodia, but then replaced with a local. Not being funny but what is your real concern here? You can always put a local sim in...

Sent from my CUBOT_NOTE_S using Tapatalk
 

 

 

" Not being funny but what is your real concern here? You can always put a local sim in... "

 

yes no problem and I fully intended to put local sim's in

but my concern started last night when I received an email from my bank in Australia Citibank which made me suddenly realise that they have  to able to contact me at all times on my Thai mobile number not only to allow me to access my account but also  in case they query any activity regarding my credit card use in the countries I'm visiting. you see when I am online and want to access my account they send out an SMS with a four digit pin number(different every time) from Australia and I get it instantly here in Thailand.

 

then you only have a very short time to enter the details otherwise you are denied access.or if I'm using my credit card  in one of those countries they may want to ask me security questions. It's a bit over the top but I guess it's  I for my own protection. That's why I need the Thai SIM   to be working everywhere I will be going.

[thecolonel]

Yes that's exactly why I have a dual sim phone so the UK banks can get in touch(when I think they need to) its just more convenient than swapping single sim, but personally I choose to have it switched off most of the time, good luck

Sent from my CUBOT_NOTE_S using Tapatalk

[sfokevin]

Just remember that when you move to a different county to turn off the previous countries data roaming or you could be in for a huge bill when you return...

 

Also make sure your True sim has been Activated by True to roam in other countries and has funds enough to work while you are out of the country

 

http://truemoveh.truecorp.co.th/international_service/travelling_abroad?ln=en

 

 

http://www3.truecorp.co.th/truemoveh/international_services/roaming_services/entry/652?ln=en

 

Edited July 19, 2017 by sfokevin

[Asiantravel]

30 minutes ago, sfokevin said:

Just remember that when you move to a different county to turn off the previous countries data roaming or you could be in for a huge bill when you return...

 

Also make sure your True sim has been Activated by True to roam in other countries and has funds enough to work while you are out of the country

 

http://truemoveh.truecorp.co.th/international_service/travelling_abroad?ln=en

 

 

http://www3.truecorp.co.th/truemoveh/international_services/roaming_services/entry/652?ln=en

 

"  turn off the previous countries data roaming or you could be in for a huge bill when you return... "
 

 

yes thanks a lot - True actually told me the same thing this morning

[boriga]

It depends on your device, but ideally put your Thai SIM in slot 2 and make sure you turn off data roaming on that slot. Then put each new SIM in slot 1 with data turned on. 

 

You only need voice call and sms capability from your Thai sim so leave it in slot 2 with data turned off and you should have no significant bills.

 

Nowadays voice / sms services work almost anywhere, not like a few years ago, data can be more complex, but a local SIM will solve that.

[Pungdo]

20 hours ago, Asiantravel said:

yes no problem and I fully intended to put local sim's in

but my concern started last night when I received an email from my bank in Australia Citibank which made me suddenly realise that they have  to able to contact me at all times on my Thai mobile number not only to allow me to access my account but also  in case they query any activity regarding my credit card use in the countries I'm visiting. you see when I am online and want to access my account they send out an SMS with a four digit pin number(different every time) from Australia and I get it instantly here in Thailand.

Last time I was home in Oz I tried to do a transfer to my Thai SBC account from the Com Bank and the SMS wouldn't work, ie I never received the pin number, I do a bank transfer every month while in Thailand and like you say the pin arrives almost instantly.

 

I have a Dual sim Samsung J5 and I had my normal AIS sim in slot 1 and a Vodaphone sim in slot 2, I tried swapping them over but i still couldn't get the text.

[edwardflory]

I had a 3 sim 3g made in China mobile, by overseas purchase delivered to USA.

Also had a NO roaming feature switch OUT of the home area - all of US was home area

Slot 1,  US Sim set to AUTOMATIC, and data

I got my AIS service activated in the US =>5<= years ago slot 2 set to AUTOMATIC in 3 hours after a call to Thailand. Data turned OFF
I got a sim in HK, slot 3 set to AUTOMATIC, switched US data OFF just to be sure it WAS off, HK data on. HK data off about 10 minutes before boarding airplane, Thai data on, Thai data not available in HK, the no data roaming feature working, US data failed also.

 

NOTE: Thai AIS sims WILL ROAM 2 networks in USA if set to ON! My feature worked NO data, I had to throw 2 switches to get roaming data from TH or HK

 

CHECK YOUR MANUAL to see the settings YOU can use, LOST your manual, usually can download from manufacturer web site in PDF

 

[RandomSand]

According to:

 http://www.worldtimezone.com/gsm.html

Quote

GSM 900 / GSM 1800 MHz are used in most parts of the world: Europe, Asia, Australia, Middle East, Africa.
GSM 850 / GSM 1900 MHz are used in the United States, Canada, Mexico and most countries of S. America.

Link: https://www.signalbooster.com/pages/what-are-the-cellular-frequencies-of-cell-phone-carriers-in-usa-canada

 

 

[Asiantravel]

5 hours ago, boriga said:

It depends on your device, but ideally put your Thai SIM in slot 2 and make sure you turn off data roaming on that slot. Then put each new SIM in slot 1 with data turned on. 

 

You only need voice call and sms capability from your Thai sim so leave it in slot 2 with data turned off and you should have no significant bills.

 

Nowadays voice / sms services work almost anywhere, not like a few years ago, data can be more complex, but a local SIM will solve that.

thanks the way you have described it is exactly what I was hoping for

[Asiantravel]

3 hours ago, Pungdo said:

Last time I was home in Oz I tried to do a transfer to my Thai SBC account from the Com Bank and the SMS wouldn't work, ie I never received the pin number, I do a bank transfer every month while in Thailand and like you say the pin arrives almost instantly.

 

I have a Dual sim Samsung J5 and I had my normal AIS sim in slot 1 and a Vodaphone sim in slot 2, I tried swapping them over but i still couldn't get the text.

did Commonwealth Bank tell you why their SMS didn't work in Australia?

otherwise I'm assuming they could have called you without any problem on your Vodafone SIM?

fortunately just regarding the PIN generation I do have a fallback position which is a tiny device Citibank provides free of charge (see picture below) which is apparently able to work anywhere in the world though I'm not familiar with the technology behind it.

so when you receive the prompt on the Internet page you press the green button on this device and you generate the PIN which you have to enter. This is instead of receiving it on your mobile phone.

but that is only for the PIN - I also want them to be able to phone me if they need to.

 

Edited July 20, 2017 by Asiantravel

[Asiantravel]

2 hours ago, edwardflory said:

I had a 3 sim 3g made in China mobile, by overseas purchase delivered to USA.

Also had a NO roaming feature switch OUT of the home area - all of US was home area

Slot 1,  US Sim set to AUTOMATIC, and data

I got my AIS service activated in the US =>5<= years ago slot 2 set to AUTOMATIC in 3 hours after a call to Thailand. Data turned OFF
I got a sim in HK, slot 3 set to AUTOMATIC, switched US data OFF just to be sure it WAS off, HK data on. HK data off about 10 minutes before boarding airplane, Thai data on, Thai data not available in HK, the no data roaming feature working, US data failed also.

 

NOTE: Thai AIS sims WILL ROAM 2 networks in USA if set to ON! My feature worked NO data, I had to throw 2 switches to get roaming data from TH or HK

 

CHECK YOUR MANUAL to see the settings YOU can use, LOST your manual, usually can download from manufacturer web site in PDF

 

did this just this afternoon

[misterphil]

"My question is if I use the SIM 1 slot temporarily for prepaid SIM’s I will buy in Japan, USA and Mexico to allow for the different standards,  will the TRUE MOVE Sim with the Thai number keep working okay in the SIM #2 slot?"

Yes ofcourse it will, its not just a SIM card holder. 

[elgenon]

I think the frequencies you said the phone is capable of are only available from ATT and T-Mobile not Sprint or Verizon in the States. ATT and T-Mobile are GSM the others are not.

[Asiantravel]

3 hours ago, elgenon said:

I think the frequencies you said the phone is capable of are only available from ATT and T-Mobile not Sprint or Verizon in the States. ATT and T-Mobile are GSM the others are not.

yes True provided me with a list of companies for the countries I will be visiting and for America ATT is the only company on the list

Edited July 21, 2017 by Asiantravel

[sandyf]

On 7/19/2017 at 7:14 PM, thecolonel said:

Yes that's exactly why I have a dual sim phone so the UK banks can get in touch(when I think they need to) its just more convenient than swapping single sim, but personally I choose to have it switched off most of the time, good luck

Sent from my CUBOT_NOTE_S using Tapatalk
 

That's what I found to be the best option. I just left the Thai sim in slot 1 and put UK sim in slot 2. The only downside is that my wife is with me and she only has a Thai sim and if I want to call her it is either via the UK sim or change the settings to the AIS sim.

[pby92]

22 hours ago, sandyf said:

That's what I found to be the best option. I just left the Thai sim in slot 1 and put UK sim in slot 2. The only downside is that my wife is with me and she only has a Thai sim and if I want to call her it is either via the UK sim or change the settings to the AIS sim.

Cheaper for you and she to only send her SMS if need than a voice call.