How every call is checked
Before any call is placed, the dialer asks the safety service: may this number be called now? The answer comes back in a fraction of a second, from memory. It is either yes, or no with one reason in plain words. The first check that fails wins.
The checks in order
Section titled “The checks in order”| # | Check | If it fails, the screen says (examples) |
|---|---|---|
| 1 | The number reads as a valid phone number | The phone number could not be read as a valid number, so it cannot be dialed. |
| 2 | The safety data is fresh (refreshed within 60 seconds) | No call is allowed right now: the compliance data could not be refreshed for over a minute. |
| 3 | Do-not-call: trap number, litigator, federal, state, your own list | This number is on the federal Do Not Call list. |
| 4 | The rules are complete (calling hours and a consent rule exist) | The calling rules are incomplete (nothing is set for calling_hours)… |
| 5 | Consent, when the strictest rule requires it | The newest permission-to-call record is 400 days old; your rules allow at most 365 days… |
| 6 | A time zone can be worked out | We cannot tell which time zone this person is in… |
| 7 | Inside calling hours in every possible zone | It is 9:40 pm where this person lives (Eastern time); calling hours end at 9 pm. |
| 8 | Not a holiday, when your rules block holidays | Today is Labor Day where this person lives, and your rules block calls on holidays. |
| 9 | Attempt limits per number, across all campaigns | This number has already been dialed 3 times in the last 24 hours and the limit is 3. It can be tried again after 7 Oct 2026 at 17:00 UTC. |
The sentences are the product’s own. The reason codes behind them, such as dnc_internal or outside_hours, are in dial-check reasons. Time-based reasons also say when to try again.
What “fail closed” means for you
Section titled “What “fail closed” means for you”The checks never allow a call when they are unsure.
- No answer means no dial. If the safety service does not answer in time, nothing is dialed. The dialer holds back and tries again.
- If the safety service stops, dialing pauses. Calls already in progress continue. Dialing resumes by itself when the service is back.
- A check that cannot be recorded is a refusal. Every check is written to the record before the answer goes back. If the write fails, the answer is “could not be checked” and the attempt is not counted.
Details worth knowing
Section titled “Details worth knowing”- The end of the window has a margin. No new call starts in the last 60 seconds of the calling hours, so a call that is still ringing does not connect after closing time.
- Attempts are counted when a check allows a call. A call the dialer then fails to place still counts. Denied checks never count.
- Do-not-call is never skipped. This includes callbacks.
- A callback skips one thing only: the consent age cap. Consent must still exist and not have run out.
- Holidays are blocked only if your rules say so. The starting value is off.
Your own campaign hours sit on top of these. See calling hours and retries.