How to Find a CISO's Phone Number (2026)

The fastest way to find a CISO's phone number is to search a people database for CISOs flagged with a phone, then pull the direct dial by person id. A switchboard gets you a gatekeeper. A direct dial or mobile gets you the CISO.

TL;DR

• Search for CISOs with hasPhone: true, size the list for free, then pull numbers only for people you will call.
• Time: about 15 minutes for one CISO, about 30 for a list of 500. Cost: 1 LeadOcean record per number pulled.
• Check the calling rules first. The API returns the number, not permission to dial it.

Prerequisites

• A LeadOcean account on the free plan: app.leadocean.io/register. Free gives you 1,000 records for life, every feature and 5 requests a second.
• An API key from the app, exported as $LEADOCEAN_API_KEY.
• curl and jq.
• A target: a company domain for one CISO, or a filter set for a list.

Step 1: Decide what you need, a switchboard or a direct dial

A main line rings reception. A direct dial or mobile rings the person. Security leaders are screened hard, and vendors are the usual reason. The main line rarely works.

LeadOcean returns each number with the source's own type label, such as mobile, direct, office or unknown. Take mobile and direct first. Treat office as a fallback, and a mobile as the number with the strictest calling rules (see Step 5).

Titles vary. Some companies say CISO, others say Head of Security or VP Information Security. Search the exact CISO title first, then widen once you know the count.

Step 2: Size the CISO list for free

Count before you spend. A count costs 0 records. Ask the MCP tool leadocean_count_leads, or send count=true with limit=1 as query parameters on the search endpoint.

curl -s -X POST "https://api.leadocean.io/v1/people/search?count=true&limit=1" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "title": ["CISO"],
    "jobLevel": ["C-Team"],
    "country": ["US"],
    "hasPhone": true
  }'

meta.total is capped at 100,000 on this call. Enum values are exact strings (C-Team, not c-team), so check spelling with leadocean_list_enum_values.

Step 3: Search for CISOs who have a phone on file

Search returns people, one record per row. Filters are arrays, the body is flat JSON, and limit runs 1 to 100.

curl -s -X POST "https://api.leadocean.io/v1/people/search" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "title": ["CISO"],
    "jobLevel": ["C-Team"],
    "country": ["US"],
    "industry": ["Banking"],
    "hasPhone": true,
    "limit": 25
  }' | jq '.meta, (.data | length)'

Page on with meta.nextCursor. One search stops at 10,000 rows (meta.depthCapped), so narrow by industry or headcount instead of paging deeper. To find one named company's CISO, use GET /v1/companies/{domain}/people and filter the title.

Step 4: Pull the direct dial

Spend records last. Each phone pull is one record, so a 25-person test batch costs 25 records on the free plan.

Take the person id from meta.source_ids.person_id on a search row and ask for the phone. This costs 1 record per call, including a call that finds nothing.

curl -s "https://api.leadocean.io/v2/people/phone?person_id=1234567" \
  -H "x-api-key: $LEADOCEAN_API_KEY" | jq

Numbers come back best first. The position in the array is the priority, and best points at the top one.

In Claude or another MCP client, the find_phone tool does the same lookup and costs 1 record.

For a list over a few hundred people, skip the loop. Start an export with POST /v1/exports and the full preset, which includes phone_1_number and phone_2_number. One export takes up to 50,000 rows, and an account gets 500,000 a day. Bulk CSV export is not on Free: it comes with Solo ($97 a month) and Agency ($497 a month, 50k rows a file).

curl -s -X POST "https://api.leadocean.io/v1/exports" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "us-cisos-with-phone",
    "filters": { "title": ["CISO"], "jobLevel": ["C-Team"], "country": ["US"], "hasPhone": true },
    "limit": 500,
    "preset": "full",
    "reveal": "email_phone"
  }'

Poll GET /v1/exports/{id}, then fetch GET /v1/exports/{id}/download. You can build the same export in the app: filter builder, column picker, price preview, then download.

Step 5: Check what you may call before you dial

Having a number is not the same as being allowed to call it. The rules differ by country, by whether the line is a mobile, and by whether you use an autodialer or a recorded message.

• The API does not return a do-not-call flag. The v2 phone endpoint omits dnc on purpose, because the field is unpopulated at source. Its absence is not clearance.
• Run your own list through the registries that apply to you before a campaign.
• In the US, the FTC's Telemarketing Sales Rule exempts most calls to a business, including from its Do Not Call provisions. The exemption does not cover calls selling nondurable office or cleaning supplies, and the ban on misrepresentation still applies (16 CFR 310.6(b)(7), checked October 2026).
• A CISO's personal mobile can carry stricter rules than a business line. Ask your counsel, and keep a suppression list.

This is not legal advice.

What you get

Expect a short list, not a dump. Every row in the slice below has a phone flag, and some pulls will return an office line rather than a direct dial. Sort by the type field and call direct and mobile first.

A free count run on 2026-10-21 with leadocean_count_leads (title CISO, job level C-Team, country US, hasPhone true). It is a phone-flag count. It is not a verified-number count.

{
  "total": 3796,
  "totalIsExact": true,
  "distinctCompanies": 2993,
  "credits": 0,
  "facets": {
    "seniority": [
      { "value": "c_suite", "count": 3677 },
      { "value": "owner", "count": 119 }
    ],
    "industry": [
      { "value": "IT Services and IT Consulting", "count": 379 },
      { "value": "Software Development", "count": 323 },
      { "value": "Financial Services", "count": 296 },
      { "value": "Hospitals and Health Care", "count": 270 }
    ]
  }
}

The phone call returns this shape. It is the response shape from the API reference, with placeholder values.

{
  "success": true,
  "data": {
    "found": true,
    "phones": [
      { "phone": "+1 415 555 0133", "type": "direct" },
      { "phone": "+1 415 555 0134", "type": "office" }
    ],
    "best": { "phone": "+1 415 555 0133", "type": "direct" }
  }
}

The title match is a keyword match, so some rows are owners of small firms who also hold the CISO title. Read the title column before you dial.

Troubleshooting

FAQ