Yes — in many cases, you can still receive calls and texts on your Primary SIM even when it has no mobile signal.
This depends on your device, network, and whether Wi-Fi Calling is enabled.
🍎 iPhone Users (Recommended Setup)
iPhones support a feature called Wi-Fi Calling over Cellular Data.
This means your iPhone can use the mobile data connection from your FlexiFone SIM/eSIM to keep your Primary SIM connected for calls and texts.
For example:
Primary SIM = your normal UK number
FlexiFone = secondary SIM/eSIM with data
If your Primary SIM loses signal, your iPhone may automatically continue receiving calls and texts using FlexiFone data.
✅ How to Enable It on iPhone
1️⃣ Enable Wi-Fi Calling on your Primary SIM
Open Settings
Tap Mobile Service / Cellular
Select your Primary SIM
Tap Wi-Fi Calling
Enable Wi-Fi Calling on This iPhone
2️⃣ Use FlexiFone for Mobile Data
Go to Settings
Tap Mobile Service / Cellular
Set FlexiFone as your Mobile Data line
Enable Allow Mobile Data Switching
3️⃣ Check It’s Working
When your Primary SIM has no signal, your iPhone may show:
“[Primary SIM] using Cellular Data”
This means calls and texts are being routed through your FlexiFone data connection ✅
🤖 Android Devices
Most Android phones do not support this feature properly.
Some devices or networks may partially support it, but reliability varies depending on the manufacturer and carrier.