Can two SIM cards on the same carrier provide meaningful redundancy?

Two SIMs on the same carrier can protect against a damaged SIM, an account problem or a plan-specific issue, but they usually share much of the same tower and core network infrastructure. That means they provide less geographical and network diversity than SIMs from different carriers.

Same-carrier dual SIM can still be useful where one service has a different APN, billing arrangement or priority, or where operational simplicity matters. For stronger redundancy, test two carriers at the actual site and confirm that each uses a genuinely useful signal path. Carrier diversity also needs sensible antenna coverage and independent account management. The right arrangement depends on the consequence of failure, the available networks and whether the site needs automatic failover or simply a backup service that can be selected manually.