List hygiene & Do Not Call

List quality drives deliverability more than volume does. How to keep yours clean and provably compliant.

Spam flagging isn't only about how many calls a number makes — it's about what happens on those calls. A stale list full of disconnected numbers, wrong numbers, and people who never asked to hear from you produces exactly the signals carrier algorithms punish: short calls, low answer rates, and complaints.

Cleaning your list is the cheapest deliverability upgrade there is — and the one most people skip while tinkering with everything else.

Before you load a list

Source honestly. Purchased lists of people with no relationship to your business are how numbers get burned (and how legal complaints start). Leads who asked for contact perform better and flag less.
Age matters. Phone numbers churn. A list older than a year should be assumed partly disconnected — expect dead dials that drag your answer rate down.
Scrub against your own suppression lists first. ClearTalk enforces its Do Not Call and Blocked from Texting lists automatically at dial/send time, but the cleanest campaigns don't load suppressed contacts at all. Export your list from Do Not Call → Export and remove matches before importing.
Use the import checks. The CSV importer under My Contacts validates every row, maps your columns, and hands you back the invalid rows as their own file to fix — don't ignore that file; it's your dead weight.

While campaigns run

Watch answer rates per campaign in Reports. A falling answer rate is your earliest deliverability warning — earlier than any spam label.
Calls that end in Wrong Number or Do Not Call results are list feedback. Persistent wrong numbers mean the source data is bad.
A call whose result is Do Not Call adds the number to your suppression list automatically — one honest "take me off your list" conversation, permanently honored, is far cheaper than a complaint.

The suppression lists are an asset

It's tempting to see the Do Not Call list as lost leads. It's the opposite: every entry is a complaint that didn't happen and a spam signal you didn't emit. Maintain them:

Import existing suppression lists when you migrate to ClearTalk (CSV import on the Do Not Call page).
Export them whenever another system dials on your behalf — your suppression list only protects channels that honor it.
Sync opt-outs outward to your CRM automatically via the webhook events, so every system you run respects the same list.

The formula

Clean list in, honest results honored, suppression synced everywhere. Combined with registered, warmed-up, rotated numbers, that's the whole deliverability picture.

For the mechanics — importing a CSV, lists versus tags versus status, and maintaining the Do Not Call list — see Contacts and lists.