Text-message codes will stop a bored attacker with a stolen password. They will not stop a SIM swap, and they will not stop the phishing kits that now relay codes in real time. If your business checked the MFA box with SMS and moved on, you have the weakest version of a strong control.
Why SMS Codes Fail
Two attacks do most of the damage. In a SIM swap, someone convinces a mobile carrier to move your number to their device, and every code meant for you goes to them. In real-time phishing, a fake login page passes your password and your code straight through to the real site while you type them. The code is legitimate. It just is not you using it.
Neither attack is exotic anymore. Phishing kits with code relay built in are sold as subscriptions, and the targets are not Fortune 500 companies. They are businesses whose staff will type a code wherever a convincing page asks for one.
The Ranking, Worst to Best
- No MFA. Password-only accounts are the first thing any attacker tries.
- SMS codes. Blocks password-only attacks. Loses to SIM swaps and real-time phishing.
- Authenticator app codes. No phone number to hijack. Still phishable in real time.
- App push with number matching. The prompt makes you confirm a number shown on the login screen, which kills the approve-fatigue attack.
- Hardware keys and passkeys. Bound to the real website. A fake login page gets nothing. This is the phishing-resistant tier insurers and frameworks now name explicitly.
Every step down that list is a real reduction in risk. Our managed IT security services team moves clients up it as part of the standard security baseline.
Your Insurance Application Already Asks About This
Cyber insurance applications have moved from asking whether you have MFA to asking what kind and where. Answering yes on the strength of SMS codes is how businesses end up with the coverage problem we described in Cyber Insurance Is Not a Security Strategy. It’s a Cleanup Budget. If a claim reveals the control was weaker than stated, the payout is at risk.
How to Upgrade Without a Riot
Nobody enjoys changing how they log in, so sequence it. Admin and finance accounts move to phishing-resistant MFA first, since they are the accounts that hurt most. Everyone else moves to app-based push with number matching next. Passkeys roll out where your platforms support them, which for Microsoft 365 is already the case. Pair the rollout with short security awareness training so staff know why the prompt changed, and fold the whole thing into the broader cybersecurity program rather than treating it as a one-off project.
SMS-based MFA beats nothing and loses to the two attacks that matter: SIM swaps and real-time phishing. The upgrade path is app codes, then push with number matching, then passkeys or hardware keys. Move admin and finance accounts first, and make sure your cyber insurance application describes what you actually run.
Not Sure What Your MFA Actually Covers?
Most businesses find out their MFA coverage is patchy the same way they find out about backups: at the worst time. We can map which accounts have which factor in an afternoon and give you the upgrade order.
You can also find us on Google to read what other Nashville businesses say about working with us. Call us at (615) 639-6326 any time.
Frequently Asked Questions About the Best MFA Method for Business
Is SMS two-factor authentication good enough for a small business?
It is better than a password alone and below the bar insurers and security frameworks now expect. SMS remains acceptable as a temporary fallback, but admin accounts, email, and anything touching money should use app-based or phishing-resistant MFA. If SMS is your only option on a platform, that is worth flagging in your next vendor review.
What is the best MFA method for Microsoft 365?
Passkeys or hardware security keys where you can, and Microsoft Authenticator push with number matching everywhere else. Both are native to Microsoft 365 at no extra license cost for most tiers. SMS should be disabled as a sign-in method once stronger factors are enrolled, because attackers can choose the weakest enabled option.
Does cyber insurance require phishing-resistant MFA?
Increasingly, yes, at least for admin access, remote access, and email. Applications now ask about MFA type, not just presence. Answering with a stronger control than you actually run is worse than a gap, because a misstatement discovered during a claim can jeopardize the entire payout.
