The Lemon Fool

I would like to use dual SIM as follows:

UK SIM in UK: Data + calls + texts
Country X SIM in UK: Calls + texts only, STRICTLY NO DATA, (mainly for incoming 2FA texts)

Then when I go abroad I want:
Country X SIM in Country X: Data + calls + texts
UK SIM in Country X: Calls + texts only, STRICTLY NO DATA, (mainly for incoming 2FA texts)

Essentially, the "home" SIM would be used for almost all calls, data and texts. The "foreign" SIM would be there to receive incoming texts, mainly 2FA texts from bank, credit cards etc. I do not want to consume data on the foreign SIM.

I have a Pixel 7, which supports SIM + one eSIM.

The problem I see here, is all the advice on settings talks about "Preferred SIMs".
Preferred is no use to me, as I want the data roaming STRICTLY off at all times. Country X would be in Asia and I don't get free roaming there.

Is such a setting possible within Android ?


I presume I could do the same thing by switching roaming off at the phone company website.
However, that's an inferior solution. It's more difficult to do and more difficult to check. Also, it requires advance planning & if I suddenly flew from country X to a third country, where I get free roaming, I'd need to get to a WiFi signal to turn roaming back on.

In recent years, I have been simply putting my "foreign" SIM in a little Nokia push button phone.
That's small, light weight, boots up quickly and doesn't even have data. I believe I'm on borrowed time with this as 2G is going to be switched off in some countries (if it is even 2G). Also, I have SIM that only works in a smartphone.

I've got a dual-SIM Samsung A-something. In Settings/SIM manager you can set each which SIM is used for calls/SMS/data.
I have a work SIM that covers data/calls overseas, but texts and calls to my personal number will still get through.

My One Plus Nord2 with dual SIMs is terrific for UK and foreign SIM cards. Each SIM is selectable and configurable within Android settings.

James wrote:I've got a dual-SIM Samsung A-something. In Settings/SIM manager you can set each which SIM is used for calls/SMS/data.

Is your menu setting a "preferred SIM" or is it a strict setting that will not be overruled ?

For example, my UK SIM uses EE.
If, my foreign SIM used Vodafone in the UK, just as soon as I go somewhere with a poor EE signal, would it try to make a data connection via the Vodafone network ? That's still respecting a preference for the EE SIM, until the EE signal drops out.

Within my SIM manager menu, there is an option called "Data Switching".

This can be enabled or disabled - if disabled, it means that the phone won't switch between SIMs if your preferred SIM can't access data.

I use this regularly on a Motorola Android phone as I have a Spanish SIM and a UK SIM and only want them to use data when I'm in the respective country.

jaizan wrote:For example, my UK SIM uses EE.
If, my foreign SIM used Vodafone in the UK, just as soon as I go somewhere with a poor EE signal, would it try to make a data connection via the Vodafone network ? That's still respecting a preference for the EE SIM, until the EE signal drops out.

I have a Pixel 7, and used dual SIMS in USA recently.
Physical SIM was a UK Lebara SIM.
eSIM was an Airalo USA data SIM.

The Airalo SIM is now expired, so I can't check what options were available regarding "preferred".

However, I am pretty sure that is is possible to turn off either mobile data or data Roaming on either SIM - these options are available on my physical SIM on it's own at present.

elkay

jaizan wrote:

James wrote:I've got a dual-SIM Samsung A-something. In Settings/SIM manager you can set each which SIM is used for calls/SMS/data.

Is your menu setting a "preferred SIM" or is it a strict setting that will not be overruled ?

For example, my UK SIM uses EE.
If, my foreign SIM used Vodafone in the UK, just as soon as I go somewhere with a poor EE signal, would it try to make a data connection via the Vodafone network ? That's still respecting a preference for the EE SIM, until the EE signal drops out.

I think that the "Preferred SIM" title is probably a poor choice on the part of whoever designed this particular part of Android's SIM management screen. "SIM Choice" would have been a better title IMHO.

Like James, I have a dual-SIM Galaxy A something and I have never found that the phone has over-ridden a preferred SIM setting in the way you suggest. For data (but not calls and messages) it is possible to allow the phone to switch to the other (non-preferred) SIM via the Data Switching control (as mentioned by the the0ni0nking). I keep that control off. For calls and messages, the "preference" only controls outgoing stuff.

modellingman

jaizan wrote:

James wrote:I've got a dual-SIM Samsung A-something. In Settings/SIM manager you can set each which SIM is used for calls/SMS/data.

Is your menu setting a "preferred SIM" or is it a strict setting that will not be overruled ?

For example, my UK SIM uses EE.
If, my foreign SIM used Vodafone in the UK, just as soon as I go somewhere with a poor EE signal, would it try to make a data connection via the Vodafone network ? That's still respecting a preference for the EE SIM, until the EE signal drops out.

It says preferred SIM, but it takes that preference and applies it without it being over-ridden.

James wrote:

jaizan wrote:
Is your menu setting a "preferred SIM" or is it a strict setting that will not be overruled ?

For example, my UK SIM uses EE.
If, my foreign SIM used Vodafone in the UK, just as soon as I go somewhere with a poor EE signal, would it try to make a data connection via the Vodafone network ? That's still respecting a preference for the EE SIM, until the EE signal drops out.

It says preferred SIM, but it takes that preference and applies it without it being over-ridden.

If I remember correctly there used to be a way that you could elect at a point in time to switch to the "other" for a call/message - so preferred makes a bit of sense in the context of "default for outgoing" while both with be active for incoming calls & messages.
It does sound a bit confusing though for data use