# B2B Prospect List: Build It Yourself or Buy It?

> A prospect list identifies potential customers, whether companies or individual business locations. Learn how to build one from Sirene, France's business register, evaluate a purchased database, and comply with the law.

Source: https://scalon.fr/en/blog/b2b-prospect-list

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[← The blog](/en/blog)

Prospecting

Build a list using the Sirene register or buy one: what each option offers, five questions for evaluating a database, and what the law says.

By [Valentin Morterol](https://www.linkedin.com/in/valentin-morterol/) · Co-founder of Scalon

The short answer

To build a B2B prospect list, start with the Sirene register (the French national business register): it identifies business locations, but you will need to find their contact information separately. Buying a list is faster; if you do, require a source, a date, and a reason for including each row. According to France's Code de la consommation (the Consumer Code), since August 11, 2026, calling a consumer requires prior consent.

Get the list of businesses in your market, with the contact details available: tell us which one.

Published on October 23, 2026

## In this article

- What is a prospect list?
- Why do you need a sales prospect list?
- How do you judge the quality of a prospect database?
- Buying or renting a prospect list: what you really get
- How do you build your B2B prospect list from the Sirene register?
- Buying a prospect list: what the law says
- Keeping the list up to date and linking it to your CRM
- Build a prospect list or have it prepared?

## What is a prospect list?

A prospect list is a database of potential customers, companies or individuals, used to run targeted sales campaigns.

Also known as a prospect database, it describes one prospect per row. In B2B (or BtoB), each row represents a company or, more precisely, a business location: an address where the business operates. Each row also includes contact details—a phone number or an email address—and information to help you decide whether to call.

Build or buy? There are three ways:

- **build it yourself**: you choose the business locations and look up their contacts;
- **buy a list**: you save preparation time, but you have to check what is delivered;
- **have it prepared**: you agree on the type of business and geographic area with the provider, then review a sample.

To decide, try building a list of ten stores: track the time you spend and the usable contacts you find, then review a sample of a prepared list and compare its total price with the work involved in building your own.

## Why do you need a sales prospect list?

The list says which companies your sales reps can call, email or visit. It is the list of business locations your sales reps will contact, and it comes before the script, the tool or the email sequence. In a [sales prospecting plan](/en/blog/sales-prospecting-plan), the list comes right after the goal and the target. When your team reaches out to potential customers directly (outbound prospecting), its campaign is only as good as its list.

A list doesn't sell for you. It tells you who to contact.

## How do you judge the quality of a prospect database?

A long list is not a good list. Ask these five questions of any prospecting database:

- Does the record match your target business type and geographic area?
- What is the source and date of the information?
- Is the business location still operating and within the target area?
- Can you reach the prospect by phone or at a valid email address?
- Does the list explain why the record is included?

The last question often goes unanswered. A qualified database answers that question with a written reason for every row. A fictitious example: "auto repair shop in Rennes, activity stated on its website," with the source page and the date it was consulted.

A complete record might look like this (also a fictional example): restaurant in Bordeaux; address of the business location; phone number found on its Contact page; URL of the source page and date consulted; reason it is listed; already a customer: no. These are the columns to ask for.

How many contacts do you need? Base the size of your database on what your team can manage, rather than aiming for a high row count. Prospect records that nobody calls earn nothing. What each row should hold to prepare the call is shown in our [prospect profile template](/en/blog/prospect-profile-template).

## Buying or renting a prospect list: what you really get

Buying or renting a company list gives you a ready-made list, fast. You filter by industry and by area, and the list arrives in a few clicks. To launch a first campaign, the time savings are real. Renting a list gives you the right to use it for a contractually defined period or number of uses; whether you buy or rent, review the usage rights in the contract.

A purchased list does not always explain why a record matches your target criteria or give the source and date of the information. Before paying, apply the five questions above to a sample: you will see which rows are usable, instead of finding the off-target rows on the phone, one by one.

Buying leads is a different product. A purchased lead is a contact who has already shown interest. A prospect list identifies companies that have not asked you to contact them.

Where do you buy a reliable list? The answer depends less on the seller than on the list itself. The criteria above apply to any database, bought or built.

**Prospecting local businesses?** Get the list for your market, your area and your target, ready to call.

## How do you build your B2B prospect list from the Sirene register?

The Sirene register lists companies and their business locations. It is the public starting point for building your list in five steps.

1. **Define the target.** Choose a type of business, using its NAF code (the French code identifying its primary business activity, also called an APE code), and a geographic area.
2. **Download the [Sirene database](https://www.data.gouv.fr/datasets/base-sirene-des-entreprises-et-de-leurs-etablissements-siren-siret).** It is published under the Licence Ouverte 2.0 (an open license that allows free reuse). The full ("stock") files are updated every month.
3. **Remove businesses that have ceased operations.** The Sirene file also includes companies that have stopped operating. Keep only the active ones.
4. **Respect the disclosure status.** An individual, such as a sole proprietor, can object to the disclosure of their data: their record is then marked "P" for partial disclosure. As the user, you must take each individual's latest disclosure status into account before reusing their record.
5. **Find the contact.** Sirene identifies the business location; the contact comes from elsewhere: its website, a directory, a call.

What about LinkedIn?

LinkedIn and Sales Navigator are tools for social selling (prospecting through social networks). They start with people rather than the business locations in a geographic area. They complement the list without replacing it.

Each step takes time, and a sales rep who builds lists is not prospecting in the meantime. The [qualification time calculator](/en/tools/qualification-time) estimates this cost for your team.

## Buying a prospect list: what the law says

As the CNIL (France's data protection authority) explains, the GDPR regulates the sale of customer lists but does not prohibit it. The regulations govern how you use the list, particularly for phone outreach.

Since August 11, 2026, soliciting a consumer by phone requires their prior consent. The [Code de la consommation](https://www.legifrance.gouv.fr/codes/section_lc/LEGITEXT000006069565/LEGISCTA000032221441/2026-08-11) requires it to be free, specific, informed, unambiguous and revocable. The business must prove this consent.

The ban also applies when the call goes through a third party acting on behalf of the business. Anyone who benefits from unlawful calls is presumed responsible, regardless of which list was used.

This rule targets the consumer, not the business: the DGCCRF (France's consumer protection and fraud control authority) describes phone solicitation as the situation where "a business contacts a consumer by phone". Still, check your case before a B2B calling campaign.

Email, fax, and automated calling systems are governed by a different provision: Article L. 34-5 of the Code des postes et des communications électroniques (the French postal and electronic communications code).

## Keeping the list up to date and linking it to your CRM

A list ages from the day it is delivered. Business locations close, contacts change jobs or phone numbers. Update the list regularly; Sirene's monthly full-file releases can help you identify closures.

The CRM is the tool; the list is the data. Before importing a row, match it against the accounts you already track, for example using its SIRET number (the fourteen-digit identifier for a French business location). That way you avoid duplicates and don't solicit a customer who already has a relationship with you. Duplicates already in the list can be removed with a few formulas: see how to [deduplicate a customer file in Excel](/en/blog/deduplicate-customer-file-excel).

Need the list for your market? We send it with the contact details available, for the scope you choose.

## Build a prospect list or have it prepared?

Building takes time. Buying doesn't tell you where a row comes from. You can also have a provider prepare a verified list for your type of business and geographic area, known as a market map; compare what the provider verifies and which updates are included in the price.

Scalon does this work. We start with a thirty-minute scoping call to define the type of business and geographic area, then collect data area by area. A human review settles the borderline cases before delivery.

Each row includes a score out of 100 showing how well the business location matches your criteria, a yes-or-no verdict (does it meet those criteria?), and a written explanation of the decision. It also includes indicators specific to your type of business, such as an accreditation or visible equipment, along with the results of matching the record against your CRM. The list arrives as CSV or XLSX for your spreadsheet, or through an API (a direct connection between software tools), under a twelve-month license, with the updates included in the plan.

A count tells you how many business locations exist. A prospect list tells you which ones to call, and why.

The scope is clear-cut: local business locations, not profiles of people. Your team remains responsible for sending messages and making calls; under the GDPR, the list provider and the party conducting outreach each have their own obligations.

The Essentiel plan starts [at €2,000 excl. VAT per year](/en/pricing). It covers one type of business, one geographic area, and one update per year; setup fees apply in the first year. Ask for a quote that specifies these fees, the first-year total excluding VAT, and the usage rights after the twelve-month term, and ask how to report errors in contact details between updates. To evaluate the actual data, request a free sample of 100 qualified business locations with no commitment, and check that the business types, geographic area, and contact details are correct.

## Sources

- [Base Sirene des entreprises et de leurs établissements, data.gouv.fr](https://www.data.gouv.fr/datasets/base-sirene-des-entreprises-et-de-leurs-etablissements-siren-siret)
- [Consentement au démarchage téléphonique, Code de la consommation, Légifrance](https://www.legifrance.gouv.fr/codes/section_lc/LEGITEXT000006069565/LEGISCTA000032221441/2026-08-11)
- [Les règles du démarchage téléphonique s'imposant aux entreprises, DGCCRF](https://www.economie.gouv.fr/dgccrf/les-fiches-pratiques/les-regles-du-demarchage-telephonique-simposant-aux-entreprises)

The list for your market, your area and your target: we send it within two business days.

More on this topic

- [Qualifying a B2B Prospect Database](/en/blog/qualify-b2b-prospect-database) : Quality criteria and how to check the contacts in a prospect file.
- [Google Maps Scraping: API, Data and Legal Rules in 2026](/en/blog/google-maps-scraping) : What the extracted file holds, what the API allows and the legal limits.
- [B2B data enrichment: sources and CRM](/en/blog/b2b-data-enrichment) : What data to add to your database, from which sources and with which tools.

[All articles →](/en/blog)