Lock Down Your Number: The SMS Security Settings Every Phone Plan Should Have Enabled
Your phone number is more powerful than most people realize. It's the key to your email, your bank, your family calendar. That makes it a valuable target.
The most dangerous attack is called a SIM swap (or port-out scam). A fraudster calls your carrier, pretends to be you, and convinces a rep to transfer your number to their SIM card. From that point on, every text meant for you — including two-factor authentication codes — goes to them instead. Accounts fall like dominoes.
The good news: every major U.S. carrier now offers free, user-controlled locks to stop this.
Here's your carrier-by-carrier checklist.
Why This Matters If You Use SMS for Anything Important
When your phone number is hijacked, any service that authenticates you by text — your bank, your email, your Google Calendar, and yes, your TextConcierge subscription — becomes accessible to whoever controls your number.
Enabling these protections takes under five minutes. Here's how.
AT&T: Wireless Account Lock + Security Passcode
AT&T officially rolled out its strongest protection, Wireless Account Lock, to all users in July 2025. When enabled, it blocks 12 types of account changes — including SIM swaps, eSIM transfers, number ports, and billing updates. Even AT&T employees cannot make changes while the lock is active.
What to enable:
- Wireless Account Lock — blocks SIM swaps, number porting, device upgrades, and billing changes all at once
- Security Passcode — a PIN required before any significant account change is processed
How to set it up:
- Open the myAT&T app (this is the only way to enable Wireless Account Lock — it's not available on the website)
- Go to your line settings and toggle Wireless Account Lock on
- While you're there, set or confirm your Security Passcode under account settings
Pro tip: Remember to temporarily disable the lock if you're doing a legitimate upgrade. Re-enable it immediately after.
Verizon: SIM Protection + Number Lock + 2FA
Verizon has had the most robust protection suite the longest. They actually split the controls into two separate toggles — which means you need to enable both.
What to enable:
- SIM Protection — blocks unauthorized SIM or eSIM swaps and device changes
- Number Lock — prevents your number from being ported out to another carrier; while active, no one can generate a Number Transfer PIN
- Two-Factor Authentication (2FA) — adds authentication via app notification, link, or one-time code for account logins
- Account PIN — required when calling customer service, blocking social engineering attacks
How to set it up:
- Open My Verizon app and go to Account → Profile & Settings → Security Settings
- Toggle SIM Protection on for each line
- Toggle Number Lock on for each line
- Enable Two-Factor Authentication from the same Security Settings menu
- Confirm or set your Account PIN
You'll get a confirmation text each time you toggle these on or off — which is itself a useful alert if someone ever tampers with your settings.
T-Mobile (and Metro by T-Mobile): Enhanced SIM Security
T-Mobile overhauled its SIM protection system in 2025 and now offers a more comprehensive per-line toggle system.
What to enable:
- SIM Protection — locks each line against unauthorized SIM changes; in-store removal requires a photo ID
- Port Out Protection (Account Takeover Protection) — blocks number porting to another carrier
- Account PIN — a 6–15 digit PIN required to verify your identity with customer service; your number cannot be ported without it
How to set it up:
- Open the T-Life app or sign in at t-mobile.com
- Go to Account → select a line → Manage add-ons → Services
- Enable SIM Protection and Port Out Protection for each line
- Go to your account profile settings and set or confirm your Account PIN
Important: These are per-line settings on T-Mobile. If you have multiple lines on a family plan, repeat the process for each one.
Other Carriers: Xfinity Mobile, Visible, Spectrum Mobile
If you're on an MVNO (a carrier that runs on a major network's infrastructure), check for these equivalents:
- Xfinity Mobile: Offers a Number Lock feature — log in to your account online to enable it
- Visible (Verizon network): Offers Line Lock — find it in your Visible account security settings
- Spectrum Mobile: Offers Account Fraud Protection, but it's off by default — go to account settings to turn it on
- Google Fi: Offers a SIM lock setting within the Fi app under security
Universal Settings That Apply Everywhere
Regardless of your carrier, these steps apply to every phone plan:
1. Change your SIM PIN
Every SIM ships with a default PIN (AT&T's is 1111; many others default to 0000 or 1234). Change it immediately.
- On iPhone: Settings → Cellular → SIM PIN
- On Android: Settings → Security → SIM card lock
2. Set a strong, unique account PIN Your carrier account PIN is different from your SIM PIN. Don't reuse a PIN you use elsewhere, and avoid obvious choices like birthdays.
3. Enable account change alerts Most carriers will text or email you when a SIM is changed or a number is ported. Make sure these notifications are active in your account profile.
4. Stop using SMS for 2FA on critical accounts This one is counterintuitive if you love TextConcierge, but for your bank, email, and password manager — switch to an authenticator app like Google Authenticator or Authy. SMS 2FA is better than nothing, but these accounts are too important to leave dependent on your phone number's security.
A Quick Reference Checklist
| Carrier | Feature | Where to Enable |
|---|---|---|
| AT&T | Wireless Account Lock | myAT&T app → Line Settings |
| AT&T | Security Passcode | myAT&T app → Account Settings |
| Verizon | SIM Protection | My Verizon app → Security Settings |
| Verizon | Number Lock | My Verizon app → Security Settings |
| Verizon | 2FA | My Verizon app → Security Settings |
| T-Mobile | SIM Protection | T-Life app → Account → Manage add-ons |
| T-Mobile | Port Out Protection | T-Life app → Account → Manage add-ons |
| All carriers | Account PIN | Carrier app → Account/Profile Settings |
| All carriers | SIM PIN change | Phone Settings → Cellular/Security |
| All carriers | Change alerts | Carrier account profile → Notifications |
The Bottom Line
Your phone number is a master key. It takes about five minutes to put a lock on it.
If you're using TextConcierge to coordinate your family's schedule, notes, and daily life, the last thing you want is someone else taking control of the number that drives it all. Enable these settings today — and while you're at it, make sure every adult on your family plan does the same.