1. Agree how you will call back.
Use a number you already know, rather than a number supplied during an urgent request. If you cannot reach the person, check with another trusted contact. Agree this while everyone is calm.
The FTC’s family emergency scam guidance explains why a familiar voice alone is not enough and recommends calling or messaging through a known number.
2. Choose your extra check.
A traditional family safe word is a private word you agree in advance. It needs no app, but you need to remember it and agree a replacement if it becomes known.
The HiSign app replaces a shared safe-word with a secure rotating phrase pair. Each person needs the app on their own phone and adds the other person in advance, in person. Later, both people read and compare the current phrases.
3. Try it before you need it.
If you choose HiSign, install it on both phones and add each other in person using QR or NFC. Try a calm practice call. Open the contact, read “You say,” and compare the words you hear with “They say.” Your contact does the same.
Try using a headset or speakerphone so you can read your screen while talking. Find what works for both of you.
4. Make the next step clear.
If a check is unavailable, the phrases do not match, or the request still feels wrong, pause. Follow your callback plan before acting. A mismatch alone does not prove a scam, and a match is not an instruction to send money or share access.
A matching phrase pair shows both devices hold the established relationship secrets for the current minute. It does not by itself prove who is speaking or rule out relay or coercion.
Prepared by Insight Velocity LLC, the maker of HiSign. September 12, 2026. App privacy policy.