Do-Not-Contact (DNC) list
A Do-Not-Contact (or Do-Not-Call) list is a record of people who have opted out of your outreach — or registered on a government DNC registry — whom you must not contact again. Honoring it is both a legal requirement (TCPA, GDPR, CAN-SPAM) and a deliverability/reputation safeguard.
How it works
Opt-outs (STOP replies, unsubscribe clicks, verbal requests) and registry entries are added to a suppression list that every channel checks before sending or dialing.
Why it matters
Contacting someone who opted out generates complaints, legal exposure and blocklist risk. The suppression must be cross-channel — a STOP on SMS should also stop email and calls.
What is the difference between the national registry and an internal DNC list?
The National Do Not Call Registry is run by the FTC and lists consumer numbers whose owners do not want telemarketing calls. Your internal list holds everyone who told your company to stop, on any channel, plus addresses and numbers you chose to exclude such as competitors, current customers in a renewal, or hard bounces. The two overlap but neither replaces the other.
A number can be absent from the national registry and still be on your internal list because that person replied STOP last month. It can also be on the registry while an exemption, such as an established business relationship, applies. Counsel should confirm which exemptions fit your use; the list logic should never assume one.
What should the suppression key be: email, phone or person?
Suppress at the person level and store every identifier that points to them. If a prospect unsubscribes from an email, the record should also block their mobile, their WhatsApp number and their LinkedIn profile. Matching only on the exact email string misses the case where the same person is imported again under a second address from a new data vendor.
Normalise before matching. Phone numbers belong in E.164 form so that a local format and an international format of one number resolve to the same key. Emails should be lowercased and trimmed. Domain-level entries let you block an entire company that asked to be left alone. Running imports through email verification first also removes bad addresses before they ever get a chance to bounce.
How often does the list need to be refreshed?
Internal opt-outs should apply immediately, at the moment they are received, because a follow-up already sitting in a queue can go out minutes later. For the national registry, the Telemarketing Sales Rule generally requires sellers to use a version of the registry obtained within the previous 31 days.
A hypothetical shows why a stale scrub hurts. A team uploads 10,000 numbers on the 1st and dials them over six weeks without re-checking. Anyone who registered during that window is now being called against their stated wish. Re-scrub each list before each campaign wave, and treat a list older than a month as unscrubbed. Log the scrub date on the list itself so anyone can see its age.
How do you test that suppression actually works?
Add a seed contact you control, enroll it in a live sequence across two channels, then send STOP from the phone. Check that the pending email step is cancelled along with the next SMS, and that no call task remains on a rep's list. Repeat with an unsubscribe click and with a manual DNC entry. In Autocloz the one suppression engine covers all five channels, and the unified inbox shows the opt-out reply next to the cancelled steps. For broader DNC compliance practice, keep a dated log of each test.
How Autocloz handles it
Autocloz maintains one suppression engine across all five channels: a STOP, unsubscribe or DNC entry on any channel instantly blocks the contact everywhere, with an audit trail.
FAQ
Should DNC be per-channel or global?
Global. An opt-out on one channel should suppress the contact across every channel. Per-channel-only suppression is how teams accidentally keep contacting people who asked them to stop.
Related terms
The TCPA is a U.S. federal law that restricts telemarketing calls, autodialed and prerecorded calls, and unsolicited texts. It requires prior consent for certain contact, honors the Do-Not-Call registry, and enforces calling-time windows — with statutory damages per violation that make compliance a real financial risk.
A2P 10DLC is the U.S. framework for sending Application-to-Person text messages over standard 10-digit long-code numbers. Carriers require businesses to register their brand and campaigns (use cases) to send A2P SMS legitimately, with throughput and trust scores tied to that registration.
DLT (Distributed Ledger Technology) registration is India's TRAI-mandated framework for commercial SMS. Businesses must register as an entity, register sender IDs (headers) and message templates on a DLT platform, and only send pre-approved content — otherwise messages are blocked.
Cold calling is the practice of phoning prospects who have had no prior contact with your company to introduce a product or service and open a sales conversation. It remains a direct outbound channel in B2B sales, though modern practice pairs it with research and multichannel context rather than dialing unqualified lists blindly.
Sources
Want this applied to your setup?
This is a reference page. If you have a specific question about your own outreach, leave your email and a human on our team will reply.