Truecaller Dual SIM Setup: Complete Android Guide (2026)
Truecaller works on dual SIM Android phones but with one key limitation: it can only be registered to one phone number at a time. Caller ID works for calls arriving on both SIMs, but auto-blocking and spam reporting are tied to the registered SIM. This guide covers the correct configuration for both SIMs and fixes for missed identifications.
How Truecaller Works with Dual SIM
Truecaller registers one phone number per account. On a dual SIM device, you register with one of your two numbers — typically your primary SIM. Here is what that means in practice:
What works on both SIMs
Truecaller identifies incoming callers regardless of which SIM slot the call arrives on, as long as the device has an active internet connection. Caller ID display works for SIM 1 and SIM 2 calls equally.
What is tied to your registered SIM only
Your Truecaller profile, spam reporting, block list and Premium features are linked to the number you registered with. Other users see your registered SIM’s profile when you call them — not your second SIM.
What does not work on the second SIM
You cannot register your second SIM number as a Truecaller account on the same device, and you cannot have two Truecaller accounts active simultaneously on one Android device.
Step-by-Step Dual SIM Setup
- Install Truecaller and register your primary SIM. Download Truecaller and register with your main number — the one you use most for calls and contacts. This becomes your Truecaller identity.
- Set Truecaller as the default caller ID app. This applies to both SIMs: go to Settings → Apps → Default Apps → Caller ID & Spam and select Truecaller.
- Configure mobile data on the SIM that receives most calls. Truecaller makes a live database lookup on every incoming call, so the internet connection must be active when the call arrives. Go to Settings → SIM & Network → Mobile Data and select the SIM receiving most calls. On Android 12 and later you can enable data on both SIMs simultaneously — check your device settings.
- Grant all required permissions. Grant Phone, Contacts and Call Log permissions — these cover activity on both SIM slots: Settings → Apps → Truecaller → Permissions → Allow all.
- Set battery usage to Unrestricted. This is especially important on dual SIM devices, where Android may be more aggressive about killing background services: Settings → Apps → Truecaller → Battery → Unrestricted.
Best Data Configuration
| Configuration | Caller ID reliable on | Auto-block reliable on | Recommendation |
|---|---|---|---|
| Data on SIM 1 only | SIM 1 only | SIM 1 only | Switch data to the most-used SIM |
| Data on SIM 2 only | SIM 2 only | Partial | Register Truecaller on SIM 2 |
| Data on both SIMs | Both SIMs | Both SIMs | Best configuration |
| Physical SIM + eSIM | Both SIMs | Registered SIM better | Register with the eSIM number if it is your primary |
Many flagship Android phones in 2026 support one physical SIM plus one eSIM. Truecaller handles this combination identically to two physical SIMs. If you use the eSIM as your primary number, register Truecaller with the eSIM number for best results.
Common Dual SIM Problems and Fixes
Caller ID works on SIM 1 but not SIM 2
This is the most common dual SIM issue, and the cause is almost always that mobile data is active on SIM 1 only. When a call arrives on SIM 2, Truecaller tries to look up the number via SIM 2’s network and fails because data is not enabled on that slot. Fix: enable data on both SIMs simultaneously in network settings, or switch your data SIM to match the SIM receiving most calls.
Truecaller shows my SIM 2 calls under my SIM 1 profile
This is expected behaviour. Your Truecaller account is linked to SIM 1. When you call someone from SIM 2, they see an unknown number or the crowd-sourced name associated with SIM 2’s number — not your Truecaller profile. The fix is to register a separate Truecaller account for SIM 2, which requires a second device or switching SIMs.
Truecaller not showing during calls on eSIM
eSIM support in Truecaller is fully functional in the current app version, but earlier versions had issues. Update Truecaller if you are using an eSIM slot, and confirm your eSIM is set as the preferred SIM for data if it is the one receiving most calls.
Auto-block not working for SIM 2 numbers
Truecaller’s auto-blocking engine is tied to the registered SIM. Spam calls arriving on SIM 2 may not be auto-blocked as aggressively as SIM 1 calls. Workaround: manually add persistent spammers to your block list, which applies to both SIMs.
Frequently Asked Questions
Can I register both SIM numbers with Truecaller on one phone?
No. Truecaller allows one active account per device. To have both numbers on Truecaller, you would need to use the second number on a different device, or switch between accounts — which requires re-verification each time.
Does Truecaller caller ID work on calls from both SIM slots?
Yes, caller ID identification works for incoming calls on both SIM slots, provided your device has an active internet connection. The limitation is that auto-blocking, spam reporting and your profile are tied to the registered SIM only.
Why does Truecaller only show caller ID sometimes on my dual SIM phone?
The most common cause is that mobile data is active on a different SIM than the one receiving the call. Truecaller needs internet access on the same SIM slot (or via Wi-Fi) when the call arrives. Enable data on both SIMs, or switch your data SIM to match the SIM getting most calls.
