Around 35 million US mobile numbers are disconnected and made available for reassignment each year, according to the FCC. After a 45-day aging period, a relinquished number can be issued to someone new — and any consent you held for the previous subscriber becomes worthless.
This is one of the more unfair-feeling TCPA exposures, because a caller can do everything correctly at collection time and still end up liable. The RND exists to give those callers a defence.
How a query works
You submit two data points: the phone number, and the later of (a) the date you obtained consent or (b) the last date you verified the consumer was still on that number. You get one of three answers:
| Response | Meaning | Safe harbour? |
|---|---|---|
| Yes | Permanently disconnected since your date — likely reassigned | No. Do not call without fresh consent. |
| No | Not disconnected since your date | Yes, if the answer proves wrong. |
| No Data | Insufficient records to determine | No, either way. |
Queries can run individually through the web interface (batches of 50), or in bulk by SFTP or API for much larger volumes.
The four elements of the safe harbour
To rely on it, you must establish all four:
- You had prior express consent to call the number before it was reassigned;
- You called the number after reassignment;
- Before calling, you checked the number against the most recent RND data and received “no”;
- The call happened because the database erroneously returned that “no”.
Element one does the most work
The safe harbour cannot rescue a call you never had consent to make. It protects a caller whose valid consent was defeated by reassignment — not one who lacked consent in the first place. If your consent records are weak, the RND does not help you.
Two things the RND will not do
It does not catch wrong numbers. The RND answers one question: has this number been permanently disconnected since your date? If a consumer gave you a mistyped or fabricated number, it was never theirs, nothing was disconnected, and the RND returns “no” while you call a stranger. The FCC has acknowledged this gap and pointed callers toward commercial databases, which carry broader identity data.
It does not identify litigators. A serial filer's number is active and has not been disconnected, so it returns a clean “no”. That check is entirely separate.
When it is worth the subscription
The RND earns its cost where consent is old — debt servicing, renewals, long-cycle nurture, reactivation of dormant leads. The further a call sits from the consent date, the higher the chance of reassignment.
For fresh telemarketing leads called within days of opt-in, reassignment risk is low and the RND adds little. Those lists need validation, line type and a litigator check instead — which is the gap NumberBroom fills at $0.044 per row, no subscription.
Frequently asked questions
Why does consent die when a number is reassigned?
Because TCPA consent attaches to the person, not the digits. The FCC and most courts read "called party" as the current subscriber or regular user of the line. The moment a number changes hands, your consent no longer covers whoever answers.
How often should I query the RND?
The safe harbour requires checking against the most recent data. Carriers report permanent disconnections on the 15th of each month, so in practice that means re-querying monthly, and specifically after each mid-month update.
What does a 'No Data' response mean?
The database lacks enough records to answer — usually because your consent date predates the reporting requirement. No Data carries no safe harbour in either direction, so it is a risk-tolerance decision. The conservative course is not to call; the alternative is to layer commercial phone-intelligence data on top.
Does the RND cost money?
Yes. It is subscription-based, priced in tiers by query volume, from small monthly plans up to very large enterprise tiers. The administrator introduced revised pricing with additional lower tiers in April 2025. Unused queries can roll over when you renew before your term ends.