Ban Lists and Spam Prevention

Managing banned numbers, voice CAPTCHA, and rate limiting to protect your hotline from abuse.

Spam and abusive callers can overwhelm a hotline. The system gives you several tools to deal with this, all manageable in real time.

Managing the ban list

Go to the Bans page to block specific phone numbers.

To ban a single number: Type the phone number in international format (for example, +15551234567) and add it. The ban takes effect immediately — the caller will hear a rejection message and be disconnected.

To ban multiple numbers at once: Use the bulk import feature. Paste a list of phone numbers, one per line, and submit. This is useful if you have a list of known abusive numbers from a previous incident.

To unban a number: Find it in the ban list and remove it. The change is instant.

Voice CAPTCHA

Voice CAPTCHA adds a simple verification step before a caller reaches your team. When enabled, the caller hears a randomly generated 4-digit code and must enter it on their keypad. This stops automated robocalls and simple spam bots.

Turn it on or off in Settings under Spam Mitigation. You can toggle it at any time — for example, turn it on during a spam attack and off when things calm down.

Rate limiting

Rate limiting restricts how many times a single phone number can call within a set time window. This prevents a single caller from flooding your line.

Toggle rate limiting on or off in Settings under Spam Mitigation.

Dealing with a spam attack

If your hotline is receiving a high volume of spam calls:

1. Enable voice CAPTCHA immediately — this blocks most automated calls
2. Enable rate limiting to slow down repeat callers
3. Ban known numbers using bulk import if you can identify a pattern
4. Check the call log on the Calls page to identify numbers that are calling repeatedly

All of these changes take effect in real time. You do not need to restart anything.

Staff reporting

Staff members can flag a caller as spam during an active call using the Report Spam button. This adds the number to the ban list automatically.