People who ask how to prospect B2B clients usually get stuck at the same point: who to call or message. The answer may be in the registration data of your best current clients. Start with them: look up your clients' CNPJ and see each one's CNAE. The codes that repeat show what kind of company buys from you, and with them you can build a list of similar companies to approach. This guide explains the method from start to finish.
What the CNAE is and why it helps you prospect
CNAE is Brazil's National Classification of Economic Activities. Every company with a CNPJ (Brazilian company tax ID) declares a main activity and may declare secondary activities, each identified by a code. The classification is organized into levels: section, division, group, class and subclass, which is the most detailed level, with seven digits.
If you sell to companies, this is useful for a simple reason: the CNAE says what the company does, and what it does says a lot about what it buys. A trucking company buys fleet maintenance, tracking and insurance. A food manufacturer buys packaging, lab testing and cold room maintenance. An accounting firm buys software, training and digital certificates.
Since the CNPJ registry is public, you can use the CNAE to go beyond the list of people you know and reach companies that have never heard of you but share the profile of those who already buy.
Step 1: describe your ideal customer
Before thinking about codes, describe in a few lines who the client is that works well for you. Use your current clients as a reference and answer:
- What do these companies do?
- What problem do they solve with your product or service?
- What is their typical size: micro, small, mid-sized?
- Who makes the purchase decision there: the owner, a purchasing manager, the finance team?
- Is there any geographic limit to where you can deliver, or do you serve all of Brazil?
Be specific. "Manufacturers" is too broad. "Small manufacturers that make plastic parts and outsource mold maintenance" already lets you choose codes and write an approach that makes sense to the reader.
Step 2: translate the ideal customer into CNAE codes
There are two paths, and the best approach is to use both.
Look at your current clients' registration data
List your best clients, look up each one's CNPJ and write down the main and secondary CNAE codes. You will soon see which codes repeat. This is the most reliable starting point, because it comes from companies that have actually bought from you.
Search the official table
Brazil's statistics institute, IBGE, maintains the CNAE table with keyword search on the Concla website. Search for terms related to your ideal customer and read the description of each subclass, including what it covers and what it does not. That way you find neighboring codes that your current clients do not use but that describe companies with the same need.
At the end of this step, have a short list of codes split into two groups: the core codes, which describe your client exactly, and the test codes, which might work.
Step 3: build the target company list
The Brazilian Federal Revenue Service (Receita Federal) publishes CNPJ registration data in open format. There are tools, paid and free, that organize this data and let you filter companies by CNAE and other fields. The filters that help most with prospecting are these:
- Active registration status: removes companies that have been closed, declared unfit or suspended.
- Main and secondary CNAE: start with the main one, which is more precise.
- Company size: helps separate those with a budget for your price point.
- Opening date: newly opened companies and mature companies buy different things.
- City and state: only if your delivery depends on being nearby.
Do not try to download the whole country. A list of a few dozen well-chosen companies delivers more than thousands of names you will never be able to approach carefully. Start small, learn from the responses and expand.
Step 4: qualify before you approach
The registry says what the company declared, not what it does today. Before reaching out, spend a few minutes on each name on the list:
- Check whether the company has a website, social media or a Google profile, and whether it looks active.
- Confirm that it really does what the CNAE indicates.
- Look for signs that it needs what you sell: open positions in the area, expansion, new products, a change of address.
- Find out who makes the purchase decision and which channel is best for reaching that person.
Mark each company as high, medium or low priority. Start with the high ones.
| The CNAE shows | The CNAE does not show |
|---|---|
| The company's declared activity | Whether it still does that activity today |
| Registered secondary activities | Which of them generates most of the revenue |
| What kind of need it tends to have | Whether it has the budget or urgency right now |
| A profile similar to your clients' | Who makes the purchase decision there |
Step 5: approach with context
A list built from the CNAE has a huge advantage: you know what the company does before the first contact. Use it. A message that shows you understand the other company's business is far more likely to get a reply than a generic text.
How to write the first message
- Say who you are in one sentence.
- Show that you know what the company does and mention a typical problem for that kind of business.
- Explain, in one sentence, how you solve that problem for similar companies.
- End with a simple question, such as asking for a fifteen-minute conversation.
If you do not have that text ready yet, the pitch generator helps you organize your introduction in a few sentences.
Cadence and respect
A single message is rarely enough. Plan three or four contacts spaced out over a few weeks, through different channels, each one bringing something new. If the person asks not to be contacted, stop and record the request. And remember that Brazil's data protection law (LGPD) protects personal data: the CNPJ is public, but the email and phone number of an identified employee are personal data. Use contact details proportionately, tied to a professional interest, and always offer an easy way to opt out. If in doubt, consult a specialist.
An example to visualize the method
The case below is fictional and is only meant to show the reasoning. Picture a small air conditioning and refrigeration maintenance company, Clima Serra Manutenções, which serves businesses in its own region.
The owner looks up the CNPJ of his ten best clients and notices a pattern: almost all of them are restaurants, bakeries and small grocery stores, businesses that depend on cold rooms and refrigerated counters working all day long. He writes down these companies' CNAE codes and, searching the official table, finds neighboring codes, such as those for snack bars and dairy retailers, which describe businesses with the same dependence on refrigeration.
With these codes, he filters active companies in the cities he can serve, sets aside those with a website or an active profile and arrives at a short high-priority list. The first message does not talk about air conditioning in general. It talks about the loss caused by a cold room breaking down on a busy Saturday and offers a preventive assessment visit.
The point of the example: the CNAE did not make the sale. It showed where to look and provided the topic for the first conversation.
Common mistakes when prospecting by CNAE
- Relying on the code alone: many companies register CNAE codes for activities they no longer carry out. Qualify before you approach.
- Lists that are too large: volume without personalization turns into spam and burns your email domain.
- Ignoring secondary CNAE codes: sometimes your ideal customer shows up as a secondary activity of companies with a different focus.
- Not measuring: note how many companies you approached per code and how many replied. That is how you find out which codes are worth it.
- Giving up too soon: outbound prospecting takes weeks to show results. Compare groups of companies, not individual messages.
Organize everything in a simple spreadsheet
You do not need an expensive system to get started. A spreadsheet with these columns will do:
- legal name, CNPJ and main CNAE;
- priority (high, medium, low);
- name and role of the decision-maker;
- date and channel of each contact;
- response and next step.
Review the spreadsheet every week. It shows where you are spending time and where the conversations that could turn into business are.
Combine the list with channels where companies meet
Prospecting by CNAE is outbound: you choose who to reach out to. It works best alongside channels where companies are also looking for you. Business rounds, industry events and referrals bring conversations with people who have already stated an interest in buying or partnering.
In an online business round, for example, each company states what it offers and what it is looking for, and B2B matchmaking suggests the conversations with the best fit. There is no guarantee of talking to companies with a specific code, but the conversation starts with interest stated on both sides. To understand the format, see how a business round works. Use your CNAE list to fill in clearly what you are looking for and to prepare your approach.
The method in summary
- Describe the ideal customer based on who already buys.
- Look up your current clients' CNPJ and note the CNAE codes that repeat.
- Expand the list of codes using the official table.
- Filter active companies by CNAE, size and, if it makes sense, region.
- Qualify each company before contacting it.
- Approach with context and a respectful cadence.
- Measure the response by code and adjust the list.
Want to add conversations with companies that are also looking for business? Your company's first online business round is on us, with an active CNPJ and once per CNPJ. See the upcoming rounds and save your spot.