Dual Sim Phone Use
Using Dual SIM Phones with myCRMSIM
Dual SIM phones can be useful when you want to operate two mobile numbers from a single device. How the two SIMs can be used with myCRMSIM depends on whether you are using SMS, RCS, WhatsApp or iMessage.
This guide explains the differences and the important limitations to be aware of.
Android — SMS
When using an Android dual SIM phone with a myCRMSIM SMS plan, both SIMs can be used separately.
‣ SIM 1 and SIM 2 can each use their own mobile number.
‣ The two SIMs can be connected to the same myCRMSIM account.
‣ Alternatively, each SIM can be connected to a different myCRMSIM account.
This means a single dual SIM Android phone can be used to manage two separate SMS numbers.
The exact SIM selection options displayed when sending messages will vary depending on the Android phone manufacturer and version of Android.
Android — RCS Messaging
RCS behaves differently from standard SMS.
Based on our testing with myCRMSIM, enabling RCS on a dual SIM Android phone allowed us to use only one SIM for RCS, rather than operating both SIMs independently.
Therefore:
‣ Do not assume that installing two SIMs will allow both numbers to operate independently through RCS.
‣ If you need to use both SIMs independently, the standard SMS configuration is the recommended setup based on our current testing.
RCS availability and behaviour can also vary depending on the phone, messaging app, mobile carrier and region.
Important:
WhatsApp — Using Two Numbers
WhatsApp supports having two WhatsApp accounts on the same phone.
To add a second WhatsApp account, WhatsApp requires a second phone number together with a second SIM, eSIM or a phone that supports multiple SIMs.
On a compatible dual SIM phone, this means you can use:
‣ SIM 1 / Number 1 with one WhatsApp account.
‣ SIM 2 / Number 2 with a second WhatsApp account.
WhatsApp allows the accounts to remain logged in on the same device and lets you switch between them without needing to log out.
Each WhatsApp account can also have its own notification and privacy settings.
For further information, see the official WhatsApp Help Center article: “How to switch accounts on WhatsApp.
iPhone — iMessage with Dual SIM
Compatible iPhones can use two active SIMs/eSIMs, and Apple allows both phone numbers to be used with iMessage.
You can therefore have two different mobile numbers available for sending and receiving messages from the same iPhone.
However, there is an important difference between having two phone numbers and having two separate iMessage devices.
The iPhone still has a single Apple Account connected to iMessage on that device.
For myCRMSIM, the iMessage sending limit is associated with the iMessage device, not with the number of SIMs installed in that device.
This means:
‣ Adding a second SIM gives you a second phone number.
‣ Adding the second number does not create a second iMessage device.
‣ The second SIM therefore does not double the myCRMSIM iMessage sending limit.
Example
If an iPhone has:
‣ SIM 1 — Number A
‣ SIM 2 — Number B
Both numbers may be available for iMessage, but they are still operating from one iPhone/iMessage device.
The myCRMSIM iMessage sending limit therefore remains the limit for that device it is not multiplied by two because two numbers are installed.
Quick Comparison
✅ Two SIMs can be used separately.
✅ Both numbers can be connected to the same myCRMSIM account.
✅ The numbers can also be connected to separate myCRMSIM accounts.
RCS on Android
⚠️ In myCRMSIM testing, only one SIM could be used when RCS was enabled.
⚠️ Do not rely on dual SIM to provide two independent RCS connections.
WhatsApp
✅ Two WhatsApp accounts can be used on a compatible phone.
✅ Each account uses its own phone number.
✅ Dual SIM or SIM + eSIM can provide the two required numbers.
iMessage
✅ Two phone numbers can be available for iMessage on a compatible dual SIM iPhone.
⚠️ Both numbers are still operating from the same iMessage device.
⚠️ Adding a second SIM does not double the iMessage sending limit.
Dual SIM phones can be useful when you want to operate two mobile numbers from a single device. How the two SIMs can be used with myCRMSIM depends on whether you are using SMS, RCS, WhatsApp or iMessage.
This guide explains the differences and the important limitations to be aware of.
Android — SMS
When using an Android dual SIM phone with a myCRMSIM SMS plan, both SIMs can be used separately.
‣ SIM 1 and SIM 2 can each use their own mobile number.
‣ The two SIMs can be connected to the same myCRMSIM account.
‣ Alternatively, each SIM can be connected to a different myCRMSIM account.
This means a single dual SIM Android phone can be used to manage two separate SMS numbers.
The exact SIM selection options displayed when sending messages will vary depending on the Android phone manufacturer and version of Android.
Android — RCS Messaging
RCS behaves differently from standard SMS.
Based on our testing with myCRMSIM, enabling RCS on a dual SIM Android phone allowed us to use only one SIM for RCS, rather than operating both SIMs independently.
Therefore:
‣ Do not assume that installing two SIMs will allow both numbers to operate independently through RCS.
‣ If you need to use both SIMs independently, the standard SMS configuration is the recommended setup based on our current testing.
RCS availability and behaviour can also vary depending on the phone, messaging app, mobile carrier and region.
Important:
This RCS information is based on myCRMSIM testing. RCS functionality continues to develop and may behave differently on different devices or networks.
WhatsApp — Using Two Numbers
WhatsApp supports having two WhatsApp accounts on the same phone.
To add a second WhatsApp account, WhatsApp requires a second phone number together with a second SIM, eSIM or a phone that supports multiple SIMs.
On a compatible dual SIM phone, this means you can use:
‣ SIM 1 / Number 1 with one WhatsApp account.
‣ SIM 2 / Number 2 with a second WhatsApp account.
WhatsApp allows the accounts to remain logged in on the same device and lets you switch between them without needing to log out.
Each WhatsApp account can also have its own notification and privacy settings.
For further information, see the official WhatsApp Help Center article: “How to switch accounts on WhatsApp.
These numbers may also be used with our SMS plan to provide SMS backup for WhatsApp
iPhone — iMessage with Dual SIM
Compatible iPhones can use two active SIMs/eSIMs, and Apple allows both phone numbers to be used with iMessage.
You can therefore have two different mobile numbers available for sending and receiving messages from the same iPhone.
However, there is an important difference between having two phone numbers and having two separate iMessage devices.
The iPhone still has a single Apple Account connected to iMessage on that device.
For myCRMSIM, the iMessage sending limit is associated with the iMessage device, not with the number of SIMs installed in that device.
This means:
‣ Adding a second SIM gives you a second phone number.
‣ Adding the second number does not create a second iMessage device.
‣ The second SIM therefore does not double the myCRMSIM iMessage sending limit.
Example
If an iPhone has:
‣ SIM 1 — Number A
‣ SIM 2 — Number B
Both numbers may be available for iMessage, but they are still operating from one iPhone/iMessage device.
The myCRMSIM iMessage sending limit therefore remains the limit for that device it is not multiplied by two because two numbers are installed.
Quick Comparison
SMS on Android
✅ Two SIMs can be used separately.
✅ Both numbers can be connected to the same myCRMSIM account.
✅ The numbers can also be connected to separate myCRMSIM accounts.
RCS on Android
⚠️ In myCRMSIM testing, only one SIM could be used when RCS was enabled.
⚠️ Do not rely on dual SIM to provide two independent RCS connections.
✅ Two WhatsApp accounts can be used on a compatible phone.
✅ Each account uses its own phone number.
✅ Dual SIM or SIM + eSIM can provide the two required numbers.
iMessage
✅ Two phone numbers can be available for iMessage on a compatible dual SIM iPhone.
⚠️ Both numbers are still operating from the same iMessage device.
⚠️ Adding a second SIM does not double the iMessage sending limit.
Devices with More Than Two SIMs
Some phones can store more than two SIMs or eSIM profiles on the device. However, in most cases, the phone will only allow two SIMs to be active at the same time.
For myCRMSIM, it is the active SIMs on the device that can be used.
This means:
‣ If your device has more than two SIMs or eSIM profiles stored, you can generally only use the two SIMs that are currently active with myCRMSIM.
‣ An additional SIM or eSIM profile that is stored on the phone but is not currently active cannot be used by myCRMSIM.
‣ myCRMSIM cannot automatically or manually rotate between inactive SIMs or eSIM profiles stored on the device.
‣ If you want to use a different stored SIM, you will need to change which SIMs are active using the phone's own SIM or eSIM settings.
Example
If your phone has four SIM or eSIM profiles stored but only SIM 1 and SIM 2 are active, myCRMSIM can only operate using SIM 1 and SIM 2.
SIM 3 and SIM 4 cannot be selected or rotated into use by myCRMSIM while they remain inactive on the phone.
Important:
Some phones can store more than two SIMs or eSIM profiles on the device. However, in most cases, the phone will only allow two SIMs to be active at the same time.
For myCRMSIM, it is the active SIMs on the device that can be used.
This means:
‣ If your device has more than two SIMs or eSIM profiles stored, you can generally only use the two SIMs that are currently active with myCRMSIM.
‣ An additional SIM or eSIM profile that is stored on the phone but is not currently active cannot be used by myCRMSIM.
‣ myCRMSIM cannot automatically or manually rotate between inactive SIMs or eSIM profiles stored on the device.
‣ If you want to use a different stored SIM, you will need to change which SIMs are active using the phone's own SIM or eSIM settings.
Example
If your phone has four SIM or eSIM profiles stored but only SIM 1 and SIM 2 are active, myCRMSIM can only operate using SIM 1 and SIM 2.
SIM 3 and SIM 4 cannot be selected or rotated into use by myCRMSIM while they remain inactive on the phone.
Important:
The number of SIMs or eSIM profiles that can be stored and the number that can be active at the same time varies by device. For myCRMSIM, you should consider the device's active SIM limit, rather than the total number of SIM profiles stored on the phone.