How to Count the Companies in Your B2B Target Market

You count a B2B target market with three filters: an industry code, a geography and an employee size band. Free government data tells you how many companies pass all three. You then multiply those companies by the real decision-makers inside each one. The result is a contact number, and that number tells you whether outbound has enough people to work with.

The industry code is NAICS in the US and SIC in the UK. In the US, the count comes from the Census Bureau's County Business Patterns. In the UK, it comes from Nomis, ONS (the national statistics office) and DBT (the government's business department).

These datasets contain two traps. Some count sites (establishments or local units) instead of companies, and an industry total is almost never your market. Below I cover each one, then walk one segment from industry code to contact number.

What number are you actually trying to count?

Three different numbers get called "the market".

1. Total companies. Everything under one industry code in one country. It looks good in a deck and tells you nothing about who to message.
2. Target companies. The part of that total that matches your paying clients on industry, size and location.
3. Reachable contacts. The real decision-makers inside those target companies that you can find and message.

Outbound runs on the third number.

To get from the first number to the third, start with the people who already pay you. Open your client records before any dataset: past and current clients first, lookalike companies second. Their industry tells you which code to pull. Their location gives you the geography, and their headcount gives you the size band.

Do the same with people. Use the titles that actually sign deals in your niche as the contact filter, never a generic "manager". That filter is what turns a company count into a contact count later on.

Whether the market is worth entering at all, and whether your deal size justifies the effort, is a separate question. That decision is covered in my market selection order.

How many contacts does your count have to produce?

Work out the number you need before you open a dataset. Otherwise you cannot tell whether 800 companies is plenty or a dead end.

My planning rule: 30 to 35 B2B sales calls a month takes at least 10,000 people contacted every month. One UK B2B client of ours got 252 appointments over 3 months, about 84 a month. In another campaign, 2,187 people contacted turned into 14 booked calls in 30 days, so a pace like that needs a list with room to run.

That is the reason to count. A niche of 2,000 companies with one buyer in each gives you 2,000 people, a tenth of the 20,000-contact first list I recommend.

Converting companies into contacts takes one multiplication:

reachable contacts = target companies x real decision-maker titles you can find in each company

The table assumes every company has someone in every title and that you can find each of them. Real lists lose people on both counts. Read the table as a ceiling. Your real number will be lower.

Then compare your number with that floor. My rule is simple: the first list holds at least 20,000 contacts. On the table, that means 10,000 companies with two real buyers each, or about 6,700 companies with three. Once a person has been through your sequence, they are no longer fresh, so the list size sets how long you can send.

Reaching out to 50 to 100 perfect-fit leads a month is a coin flip, not a strategy. You need quantity AND quality. Most people you message are busy, not ready or not interested. Volume negates luck, and every extra qualified contact is one more chance to land at the right moment.

Which code should you use, NAICS or SIC?

Official statistics are cut by industry code, so you need a code before any government count is possible.

In the US, use NAICS. Federal statistical agencies use it to classify business establishments, and it replaced the older US SIC system in 1997, according to the Census Bureau's NAICS page. The same page has search tools for the 2022, 2017 and 2012 versions, and you can search by keyword or by a 2 to 6 digit code.

In the UK, use SIC 2007. The official UK business counts on Nomis break industry down to 5-digit SIC 2007 codes. Never carry a code from one country to the other. NAICS and SIC 2007 are separate systems with separate code lists.

To pick a code:

1. Write one plain sentence about what your best clients do, using their own words.
2. Search that sentence by keyword, read the code descriptions, and choose the most specific code that still covers your clients.
3. Check the neighboring codes. Sometimes half your clients sit one code over.
4. Stop at the company type you already sell to. A wide category inflates the count with companies your case studies say nothing to.

For commercial building contractors, this lands on a NAICS code for commercial and institutional building construction in the US and the matching SIC 2007 code for construction of commercial buildings in the UK.

The code is only the first filter, and it behaves differently from a keyword search. Official data can only be cut by code, while lead tools use their own industry labels. Use the code to size the market, then use keyword search in your list tool to find the actual people. If the two numbers are far apart, one of your definitions is wrong.

How do you count US companies by industry and location?

Use County Business Patterns (CBP). The Census Bureau's 2023 CBP release, published in June 2025, gives annual counts of establishments with paid employees, plus employment and payroll, for nearly 1,000 NAICS industries.

The geography runs from national level down to state, plus metro areas, counties, congressional districts and ZIP code areas. That makes CBP the right tool for a local or state-by-state count.

One detail prevents a lot of confusion. The 2023 release defines industries using 2017 NAICS, so look up your code in the 2017 version before you pull the table, even though 2022 is the newest version.

The employment column gives you a quick check. Divide employment by the number of establishments for your code and area. If the average site has 8 people and you sell to firms with 100 or more employees, your real count is far below the headline.

Caveat: an establishment is not a company. CBP counts establishments. The CBP methodology says an establishment is not necessarily the same as a company or an enterprise. Its universe holds more than 6 million single-unit establishments and more than 2 million that belong to multi-unit firms. A contractor with one office counts once. A firm with 15 branches counts 15 times.

• You sell to the head office: CBP overstates your market, because each multi-site firm is counted once per site. For a firm count, use the Census Statistics of US Businesses (SUSB), which reports the number of firms as well as establishments. Its 2022 tables split the data by geographic area, industry, and enterprise employment or receipts size.
• You sell to each site: CBP is close to the number you want.
• You count a small area: since reference year 2017, CBP suppresses any cell with fewer than three establishments, so a narrow ZIP code and industry combination can come back blank.
• You count certain sectors: crop and animal production, rail transportation, the postal service and public administration are not in CBP. Businesses without paid employees fall outside it as well.

How do you count UK businesses by SIC code?

The UK has three official sources, and each one answers a different question.

The difference between 2.73 million and 5.7 million comes from what each source includes. The ONS figure covers only businesses registered for VAT (sales tax) or PAYE (payroll tax). The DBT figure adds unregistered businesses, estimated from household survey and tax return data. Almost all of the 5.7 million are small: 5.64 million have 0 to 49 employees.

The size bands do most of the cutting. DBT counts 38,435 medium businesses (50 to 249 employees) and 8,335 large ones (250 or more). If you sell to firms with 50 or more staff, your UK universe across every industry is 46,770 businesses.

Applying that one filter removes more than 99% of the headline figure. DBT also places each business at its head office, so a regional total shows where firms are registered. Their sites may be somewhere else.

Nomis is where you get your actual count, and it separates two units. An enterprise is the whole business. A local unit is one site belonging to an enterprise. Count enterprises if you sell to the company and local units if you sell to each site.

The ONS figures show how far apart these can be: 3.2 million sites against 2.73 million businesses.

ONS also warns that several businesses registered at one address can distort figures for small areas, so check any unusually high number for a small area before you trust it.

What should you do when the market is small?

Treat this as a separate step from counting. The count describes the market. Expanding it is a decision you make afterwards, one filter at a time.

Expand in this order:

1. Widen the geography one ring at a time: city, region, the whole country, then another country whose buyers your case studies speak to.
2. Add more real decision-maker titles per company, so the list grows deeper without getting wider.
3. Add similar companies one code over, but only where your case studies speak to their problem.
4. Keep the size band and the title filter as they are. Loosening them fills the count with people who will never buy.

Worked example: counting UK commercial building contractors

Here is one segment worked through in the UK from start to finish. The counts are round numbers for illustration. Your own Nomis query will give you the real ones.

Say 8 of your last 10 deals were with commercial building contractors that have 20 to 249 staff. Most of them are in the North West of England, and the managing director or the operations director signed each deal.

Start local where you can. A prospect who sees you are based in their city is easier to talk to.

Step 1 gives you 6% of the floor. Step 4 comes close to the 20,000 floor without dropping the size band or adding vague titles. If you sell in the US as well, count it as a separate market in CBP under the matching NAICS code, and remember that CBP counts establishments.

Use this checklist for any segment:

• Code: the most specific NAICS or SIC 2007 code that covers your paying clients
• Geography: where those clients are, starting local
• Size band: the headcount range you already sell to
• Exclusions: current clients, legal forms you do not serve, and sites when you sell to the head office
• Titles: the people who signed your past deals
• Conversion: companies x titles, compared with 20,000 and with your planned monthly sending

Count too small? - Widen the geography first. Never loosen who counts as a buyer just to make the number look better.

When should you stop counting and start building the list?

Stop counting when the contact number clears the first-list floor and covers the months you plan to send. After that, more precision is just stalling.

Then build the list itself, following a B2B lead list process worth sending to.

You can do all of this in a spreadsheet with one column per checklist line and one contact number at the bottom. If that number falls short of the floor, you find out before a single email goes out.

If you would rather have a team run the sending, see how our cold email agency works, or how appointment setting turns replies into booked calls.

If you have counted your market and want a second opinion on the numbers before you build the list, book a call and bring your spreadsheet.