How to Find Missing Phone Numbers for Your Contacts
Upload the list or connect your CRM, and Cleanlist AI verifies the emails and refills stale or missing fields from 25+ providers before your next send.
The Cleanlist AI waterfall looking for a phone number. For Ines Delacroix it tries providers in order and stops at attempt 5, the first deliverable result, which costs 10 credits. For Ben Trask all 7 attempts miss, and the charge is 0 credits.
VP of Sales · Decagon10,000+ users, from founders to full sales teams
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How does Cleanlist AI find missing phone numbers for your contacts?
Cleanlist AI's phone append service uses waterfall enrichment across 25+ data providers to find direct dial and mobile phone numbers for your existing contacts. It asks providers in sequence and stops at the first deliverable result. Each number is then normalized to E.164, checked at the carrier level for an active line, and labeled by line type so you can tell a direct line from a switchboard. On our 500-lead benchmark, Cleanlist AI found a phone number for 85% of contacts. Cleanlist AI does not screen the National Do Not Call Registry; the FTC licenses that directly to authorized sellers and telemarketers.
Why this is hard to do by hand
Phone numbers are the field most likely to be missing or stale in a B2B CRM. One reason is how the field gets filled: an office number belongs to a desk at the company, so it stops reaching the person the day they change jobs and keeps ringing for whoever sits there next. Another is number portability, which lets a subscriber keep a number when switching carriers, so the digits stay the same while the carrier and often the line type change. You end up with a column that looks full and is wrong, and most teams live with it because appending numbers by hand means the same research once per row.
A full phone column can still be unreachable
The costly phone cell is the one that's full and wrong. An office number captured two years ago still looks valid today, still passes any format check and still rings, because number portability lets the digits survive a carrier switch and the desk it belonged to stayed when its owner left the company. Nothing in the record shows the change, so the number keeps getting called and keeps producing nothing. That is why counting blanks understates the problem, and why re-validating before a campaign beats enriching once. Line type matters on the way out too: the FCC's TCPA rule at 47 CFR 64.1200 treats autodialed and prerecorded calls to cellular numbers differently from calls to desk lines, and a number that was a landline when it was captured may be a mobile by the time it is called.
What a lookup costs
Each lookup walks 25+ providers in cost order, and you're charged once for what comes back: 1 credit for a verified work email, 10 for a phone number, 11 for both. Validation is 0.5 and AI qualification is 5. A lookup that finds nothing is free, and the whole team pays from one wallet.
- Verified work emails25 leads searched23 × 123
- Phone numbersVerified before anyone calls18 × 10180
- Qualification agentFit score with reasons25 × 5125
- 25+Providers queried in cost order on a single lookup
- 98%Verified work emails on our 500-lead benchmark
- 85%Phone numbers found on that same benchmark
- 0Credits for a lookup that finds nothing
How it works.
- 01
Find the records missing a phone number
Upload your contact list or connect your CRM. Cleanlist AI shows which records have no phone number, a partial one or an invalid one.
- 02
Size the gap before you spend credits
The scan costs 0 credits, so you know how many records lack a usable number before you commit anything. A phone number costs 10 credits, and only when one comes back.
- 03
Run the phone append
Cleanlist AI asks 25+ providers in sequence for an office or mobile number for each contact. Each result is labeled by line type: mobile, landline or VoIP.
- 04
Validate every number
Each number is normalized to E.164 and checked against its country's numbering plan at no cost, then checked with the carrier. Disconnected and unreachable lines get labeled, so they never leave as valid.
- 05
Re-run before each campaign
Re-run the waterfall on the part of the list you are about to call, right before you call it. Job changes and carrier ports don't follow a calendar, and re-running at the point of use ties what you spend to the calls you make.
What you get.
Check the whole list
Validation is 0.5 credits per email, so you can run every record before a send.
25+ providers per lookup
When one provider has nothing for a contact, the waterfall asks the next one.
Fixes land in your CRM
HubSpot and Salesforce sync both ways on Pro and Enterprise, so corrected fields go back onto the same record.
A miss costs nothing
You pay for the emails and phone numbers the waterfall finds. Rows it can't fill cost 0 credits.
Manual process vs Cleanlist AI.
| Feature | Manual | Cleanlist AI |
|---|---|---|
| Providers queried per contact | One, whichever tool you bought | 25+ in a waterfall, 85% phone numbers on our 500-lead benchmark |
| Validation before export | None, you find out on the call | E.164 normalization plus a carrier level status per row |
| Line type detection | Not available | Mobile, landline, VoIP identified where the numbering plan allows |
| Do Not Call Registry screening | Obtained from the FTC directly | Not provided (the FTC licenses Registry access itself) |
| Appending 5,000 records | The same lookup repeated 5,000 times, by hand | One CSV upload processed as a single job |
| Direct line vs switchboard | No distinction (often returns main line) | Prioritizes direct office and mobile numbers |
How accurate is Cleanlist AI's data?
Cleanlist AI returned 98% verified work emails and 85% phone numbers on our 500-lead benchmark, pulling from 25+ data providers. Each lookup stops at the first deliverable result, meaning a verified or likely-valid email.
What do I get when I sign up?
A 14-day Pro trial: 250 credits, 3 seats, and every Pro feature. After it, the Free plan gives you 50 credits a month. A verified work email costs 1 credit, a phone number 10, and a miss nothing.
What data providers does Cleanlist AI use?
Cleanlist AI runs a waterfall across 25+ B2B data providers. For each record it asks one, moves to the next when that one has no match, and stops at the first deliverable result.
Can I connect my CRM?
Yes. HubSpot and Salesforce sync both ways on the Pro and Enterprise plans, and Salesloft and Lemlist take a one-way push. You can also upload a CSV, or use the REST API from Pro.
Will this prevent the problem from recurring?
A one-off cleanup won't, because people keep changing jobs. Re-run the list through Cleanlist AI before each campaign. Validation is 0.5 credits per email, and a lookup that finds nothing costs nothing.
What does it cost to fill the phone gap in a CRM?
10 credits per phone number, charged only when a number comes back. A verified email is 1 credit, and email plus phone on one record is 11. Starter is $49 a seat a month with 750 credits per seat and Pro $89 with 1,500, with 25% off annual billing. One Pro seat covers 150 phone numbers a month. New workspaces start on a 14-day Pro trial with 250 credits, and the Free plan keeps 50 credits a month after that. Prices confirmed on 29 September 2026.
How long do phone numbers stay valid?
There's no fixed shelf life, because two events invalidate a B2B phone record and neither runs on a clock. The first is a job change: an office number belongs to a desk, so it stops reaching the person the day they leave and may still be answered by someone else. The second is number portability, which the FCC defines at 47 CFR 52.21(m) as the ability to retain an existing number when switching carriers, so the digits stay the same while the carrier and often the line type change. So re-validate the slice you are about to call before each campaign.
Does Cleanlist AI check the Do Not Call registry?
No. Cleanlist AI does not screen numbers against the National Do Not Call Registry and returns no DNC status field. The FTC licenses Registry access directly to authorized sellers and telemarketers through telemarketing.donotcall.gov. The FTC's guidance Complying with the Telemarketing Sales Rule states that the prohibition on calling numbers on the Registry does not apply to business to business calls, which is why B2B research data and DNC screening are separate purchases with separate rules. Teams whose calling program falls outside that exemption should obtain Registry access from the FTC and run the screen themselves. Cleanlist AI does not provide legal advice.
Describe the job once. An agent runs it every week.
Clu turns one sentence into an agent. It searches 1B+ profiles, finds verified emails and phone numbers across 25+ providers, adds the people to your sequence and posts each run to Slack.
Weekly ICP outbound
Built by Clu from: “Every week, find 500 new people who match my ICP, get their emails and phones, and add them to Series B outbound.”
- Searched 1B+ profiles for new ICP matches500 foundPeople Search
- Ran the waterfall across 25+ providers487 emails · 412 phonesWaterfall
- Verified every email and phoneSMTP + catch-allVerification
- Added them to Series B outbound500 peopleSequences
- Posted the run to #pipelineSlackAgents
Friday 4:52 PM15 replies · 5 calls booked
Everything in the 14-day Pro trial
- Clu and agentsDescribe the job in one sentence. Clu builds the agent, runs it on a schedule or a CRM trigger and posts every run to Slack.
- People and Company SearchFind your buyers in 1B+ profiles from one sentence. Searching costs 0 credits.
- Waterfall enrichmentAsk 25+ providers in order and stop at the first verified email or phone number. 98% verified work emails and 85% phone numbers on a 500-lead benchmark.
- Email verificationRun SMTP and catch-all checks on every address before it reaches a sequence, at half a credit an email.
- ICP scoringScore every lead 0 to 100 against your ICP, with the reasons written down. The Research and Qualification skills do the digging.
- SequencesSend email from your reps' own inboxes, with call tasks. A reply stops the sequence. Sending costs 0 credits.
- CRM syncTwo-way sync with HubSpot, Salesforce and Pipedrive. Push finished lists to Outreach, Salesloft and Lemlist.
- Chrome extensionGet a verified email and phone number in one click on LinkedIn, Sales Navigator, Salesforce and HubSpot.
- MCP and APIRun the same search and waterfall from Claude or ChatGPT with 36 MCP tools, or from your own code with the REST API.
14 days of Pro, free: 250 credits, 3 seats, agents, Sequences and Clu in Slack. Then Free at 50 credits a month, or Starter at $49 and Pro at $89 a seat a month.
Hand the job to an agent.
Upload a CSV or connect HubSpot, Salesforce or Pipedrive, and run it on your own data today.
14 days of Pro, free.
Get 14 days of Pro, free.
250 credits and 3 seats. Sign up with your work email for 100 more.