Approximately 35 million US phone numbers are reassigned every year. That means a number that belonged to one of your opted-in SMS subscribers last quarter could belong to a completely different person today — someone who never gave you consent to contact them.

Under the Telephone Consumer Protection Act (TCPA), texting that new subscriber is a violation. At $500 per message — up to $1,500 if found willful — and with TCPA class action filings surging 95% in 2025, the financial exposure for enterprise brands is significant.

Airship has launched two new RND scanning features designed to help customers proactively address this risk. This post explains what reassigned numbers are, why they matter, what the FCC’s Reassigned Numbers Database (RND) does about it, and how Airship’s new tools work.

When a subscriber disconnects their phone number — by switching carriers, canceling service, or changing their number — carriers make that number available for reassignment after a minimum 45-day aging period. The new subscriber has no relationship with your brand and has never consented to receive your messages.

The problem: your SMS platform has no way of knowing the number changed hands. It still looks like an active, opted-in subscriber. Without a mechanism to check for reassignment, brands continue messaging that number, unknowingly reaching someone who never gave consent.

TCPA enforcement has intensified significantly. TCPA class action filings were up nearly 95% year-over-year through mid-2025, with an increasing number of cases filed as class actions. The financial stakes are real — settlements regularly reach into the millions of dollars, and there is no cap on aggregate damages. Reassigned numbers sit at the center of this enforcement wave.

Under FCC rules, a caller who queries the Reassigned Numbers Database before sending and receives a “no” response may be eligible for a safe harbor defense, provided the caller can demonstrate that it had prior consent, used the most recent RND data, and that any call to a reassigned number resulted from a database error. This safe harbor framework is one reason enterprise brands are incorporating RND verification into their SMS compliance programs.

The Reassigned Numbers Database was created by the FCC and went live in 2021. Carriers are required to report permanently disconnected numbers on a monthly basis. Businesses can then query the database against their subscriber lists, supplying a phone number and the date consent was obtained, and the database returns one of three responses:

• No: the number has not been reported as permanently disconnected since that date. The caller may continue messaging, and this response may support a safe harbor defense under FCC rules if the caller can demonstrate it met all applicable requirements.
• Yes: the number has been permanently disconnected or reassigned. The caller should not send to it without obtaining new consent from the current subscriber.
• No data: typically means the database does not have sufficient information for this number and date combination. This may occur when consent was obtained before carriers began reporting (April 2020 for large carriers, October 2021 for small carriers), or when the number is otherwise not in the database. Callers should exercise caution.

Service providers are required to submit their disconnect reports — covering data through at least the 10th of the month — no later than the 15th. Practically speaking, this means the RND refreshes once a month with new data by the 15th. Brands wanting to maintain safe harbor protection should run their checks after this monthly update. Maine became the first US state to mandate RND checks by law in 2024, and more states are expected to follow.

Airship now supports RND verification through two complementary products, with Airship acting as the customer’s authorized agent for the purpose of querying the database — a requirement of the FCC’s RND program.

The Full RND Scan runs your entire SMS subscriber list against the FCC’s Reassigned Numbers Database. It can be run on an ad hoc basis or on a monthly recurring schedule, and is initiated directly from the Audience section of Airship Flight Deck.

When configuring a scan, Airship customers can specify which sender IDs to include and choose between two modes:

1. Uninstall channels: Airship automatically removes subscriber channels confirmed as reassigned.
2. Report only: results are emitted as events on the SMS Compliance Stream via RTDS, giving your team full visibility without automatic action.

Carrier deactivation files — the daily feeds from carriers that flag disconnected numbers — have historically been overly aggressive. Numbers that appear on a carrier deactivation file are not always permanently disconnected; a subscriber who simply switched carriers, for example, may appear on one carrier’s file even though they still own the same number.

Previously, Airship would uninstall channels flagged in carrier deactivation files. This caused legitimate subscribers to be incorrectly removed from SMS programs.

The Carrier Deactivation RND Scan introduces a suppress-then-verify workflow:

1. When a number appears on a carrier deactivation file, Airship suppresses the channel rather than immediately deleting it.
2. While suppressed, the subscriber cannot receive outbound messages — but inbound MO keywords (including STOP and HELP compliance keywords) continue to be processed.
3. Once per month, Airship runs the suppressed channels against the RND to confirm whether permanent reassignment occurred.
4. If confirmed as permanently reassigned, the channel is deleted. If not confirmed, the channel is automatically unsuppressed and messaging resumes.

This protects your subscriber list from false positives while maintaining compliance guardrails.

If your brand sends SMS to US subscribers and has not run an RND scan recently — or ever — you should expect to find some reassigned numbers in your list. The volume depends on list age and how frequently you have cleaned it, but for lists that have not been validated, the numbers can be significant.

For ongoing programs, monthly scanning after the 17th of each month maintains list accuracy. For customers migrating to Airship or onboarding a legacy list, an initial Full RND Scan is strongly recommended before your first send.

If you have compliance or legal questions about how TCPA and RND requirements apply to your specific program, we recommend engaging your legal counsel.

This post is provided for informational purposes only and does not constitute legal advice. Please consult with your own legal and compliance teams to determine how TCPA requirements and the FCC’s Reassigned Numbers Database apply to your specific use case and program. Airship is a technology platform, not a compliance advisor. The tools provided in the Airship Service support your compliance efforts, but decisions about how to act on results — which numbers to delete, which to retain — remain with your legal and compliance teams.