SIM-Swap and Call-Forwarding Signals: The Next Layer of Account Recovery Risk

SIM-swap and call-forwarding signals are becoming important fraud checks. Businesses should rethink recovery flows that depend only on a texted OTP or voice call.

Account recovery is one of the most dangerous parts of any product. A login page may be secure, but a weak recovery flow can give attackers a side door.

GSMA Open Gateway documentation includes fraud-prevention APIs such as SIM Swap and Call Forwarding Signal. These APIs point to a bigger trend: recovery decisions are starting to use network-level risk signals instead of relying only on a code sent by SMS or voice.

Why SIM-swap signals matter

SIM-swap fraud happens when a phone number is moved to a new SIM controlled by someone else. If a service sends an OTP after that, the wrong person may receive it.

A SIM-swap signal can help a bank, fintech, or marketplace treat recent SIM changes as higher risk, especially during password resets, withdrawals, device changes, and account recovery.

Why call forwarding matters

Voice verification is often treated as safer than SMS, but call forwarding can create its own risk. If incoming calls are redirected, a recovery call may not reach the true account owner.

The Call Forwarding Signal API focuses on detecting whether call forwarding is active on a phone number. For sensitive recovery actions, that can become a useful risk check.

What product teams should review

Which actions can be completed with SMS OTP alone.
Whether a recent SIM change should trigger a cooldown.
Whether voice calls are used for high-risk recovery.
How support agents verify identity before changing phone numbers.
Whether users receive alerts after recovery changes.

Where BillioPlus fits

BillioPlus is useful for supported OTP testing and privacy-sensitive verification workflows. Developers can use virtual numbers to test how their app behaves when codes arrive, expire, or need to be resent.

For permanent account recovery, platforms should combine stable number ownership with risk checks, support controls, and backup methods.

Conclusion

The future of account recovery will not be one code and one button. It will combine OTP delivery, SIM-swap awareness, call-forwarding risk, device signals, and careful support operations. Teams that plan for this now will reduce account takeover risk later.