What Is B2B Data Coverage?

B2B data coverage is the share of the people and companies you want to reach that a database holds, with fields you can use. This page defines it, shows how to measure it, and gives the filters that test it in LeadOcean.

Key takeaways

• Coverage is measured inside your segment, not across the whole database. A big total says little about your market.
• Two things make up coverage: presence (is the person there) and fill (does the record have a working email or phone).
• On 2026-10-01, LeadOcean held 3,256 VPs of Sales in Germany. 1,128 of them were mailable and 1,073 had a phone number.
• Counting is free in LeadOcean. Test your own segment before you pick a provider.

What it is

B2B data coverage is the proportion of a defined target market, by geography, role, industry and company size, that a database holds as records with the contact fields you need.

Coverage has a numerator and a denominator. The denominator is everyone who fits your ideal customer profile, which no vendor can see exactly. The numerator is what the database returns for the same filters.

Because the denominator is unknown, you estimate it. Use a public source, such as a national business register or your own CRM, and compare.

How it works

Coverage breaks into layers. Each layer shrinks the number, and the last one is the one you can act on.

1. Define the segment. Pick country, job function, job level, industry and company size. Write the filters down so you can repeat the count.
2. Count the records that exist. This is presence: people who match the filters, with or without contact details.
3. Count the records you can reach. Add a field requirement, such as a phone number or a sendable email. This is fill.
4. Compare to a reference. Divide by an outside estimate of the market, or by a second provider's count for the same filters.
5. Check freshness. A record from last year may be stale. Ask when each record was last fetched.

A worked example

Say you sell to sales leaders at a fictional company, Acme, and your market is VPs of Sales in Germany. We counted the segment on 2026-10-01 with free count calls.

Presence is 3,256. Mailable fill is about 35% of that, and phone fill is about 33%. The phone count passes hasPhone, so it describes people with a phone number, not mailable people. The segment total uses every email status, so it counts people with a good, bad or missing email.

The fill rates matter more than the total. A provider with 3,000 reachable VPs beats one with 6,000 records where most have nothing to send to.

Coverage vs database size

People quote the biggest number on the homepage. Coverage asks a narrower question.

A related term is fill rate. Fill rate is the share of records with a given field, such as phone. It is one part of coverage, measured inside a segment.

LeadOcean's database holds 693M people, 366M with an email and 166M with a phone number, plus 63M companies. That makes about 53% of people email-filled and about 24% phone-filled across the whole set. Your segment will differ, so count it.

When it matters

Choosing between providers

Run the same segment count in each tool and compare presence and fill. A provider can lead in the US and trail in a region you sell to. Coverage by country is where vendors differ most, and the European coverage report shows the method for one region.

Selling outside the US

Most databases are strongest in North America. Check your countries before you commit. See best B2B data providers in the UK for a market-specific view.

Niche roles and small markets

For a narrow role, such as a GTM Engineer, the whole worldwide pool can be a few hundred people. A coverage gap of 20% then costs real pipeline. Count first, so you know the ceiling.

Sizing a campaign

If a campaign needs 5,000 sendable addresses and your segment holds 1,128, no amount of effort closes the gap. Coverage sets the upper limit before you write a single email.

How LeadOcean handles it

LeadOcean exposes coverage as free counts. In the MCP server, count_leads takes the same filters as search, spends no records and returns the total. By default it counts mailable people (verified, catch_all_valid, catch_all). Passing emailStatus, hasEmail, hasPhone or reachable replaces that default, so label the number by what you filtered.

Over REST, send count=true as a query parameter with limit 1 in the body. The response has an empty data array and meta.countOnly set to true. meta.total is capped at 100,000, so a very wide segment reads as a floor.

curl -X POST "https://api.leadocean.io/v1/people/search?count=true" \
  -H "x-api-key: $LEADOCEAN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobLevel": ["VP"],
    "jobFunction": ["Sales & Business Development"],
    "country": ["DE"],
    "hasPhone": true,
    "limit": 1
  }'

Run it twice, once with hasPhone and once with emailStatus, to see presence and fill side by side. Each count spends no records. Sample returned rows only after you like the numbers, because each person returned counts one record.

The filters you can count on are job function, job level, country, industry (534 values), company size and email status (13 values). A few filters, such as funding and revenue, are not supported by the free count. If your segment needs one, count without it and treat the result as wider than your list.

The dataset is refreshed monthly, and each record carries its own fetched_at date. Free gives you 1,000 records, one-off, no card. Pro is $499 a month, flat. See /pricing, and compare tools in best B2B databases.

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