Buying Company Addresses: What to Check Before You Order

First: what do you need the addresses for?

The right list depends on the channel. If you send letters, you need a deliverable address and the correct company name. If you call, you need a phone number – and, for each business, a reason that justifies the call. If you want to match your customer base, you need a unique identifier such as register court and register number. If you want to size a market, you mainly need clean industry and regional classification and can often do without contact details.

State the purpose in your request. A provider who knows it can tell you which part of their data is fit for it.

Nine checks before you order

1. Source

Where does each column come from? Register data, details from legal notices (Impressum) and information from websites differ in reliability and age. “From various sources” is not an answer. Also ask on what basis register data got into the list: the German commercial register only allows individual retrievals. What the commercial register contains and what it does not is covered in German Commercial Register: Which Company Data Is Public.

2. Data status

Ask for a date, not an adjective. “Continuously updated” says nothing about when a particular record was last checked. What makes sense is a reference date for the entire delivery.

3. Industry definition

Which classification is used to assign the industry, and to what depth? The official standard is the German classification of economic activities (WZ). Why “tradespeople” or “online shop” have no position of their own there is explained in WZ 2008: Using Industry Codes for Target Group Lists.

4. Contact field coverage

The total number of records is the least meaningful figure. Ask how many records in your selection contain a phone number, an email address or a website – as a number, not as “high coverage”.

5. Sample file

A sample file shows columns, spelling, character encoding and delimiters before you commit. Check whether postcodes are stored as text (leading zero), whether phone numbers are formatted consistently and whether empty fields are empty or have been padded. Our sample file with fictitious companies shows what such a file can look like.

6. Unit of a record

Does a row represent a company, a location or a person? This determines whether branches appear separately and whether a law firm with ten lawyers results in one row or ten.

7. Usage rights

May you use the data permanently and repeatedly, import it into your CRM and pass it on to service providers such as a print shop? Is disclosure to third parties excluded? With rented addresses: how many uses have been agreed?

8. Handling of personal data

Ask how the provider treats sole traders and freelancers, how it informs data subjects and what happens with objections. A provider who cannot answer leaves you with a risk you cannot assess.

9. Confirmation before payment

Get the number of records, the columns, the data status and the price for your specific selection confirmed in writing before you order.

Price per row or price per usable record?

Two offers can only be compared if you break them down to the records you can use for your purpose. A made-up calculation example – not the prices of any particular provider:

The seemingly more expensive offer costs half as much per business you can call. For a postal campaign the calculation would look different, because there the address is what counts.

What a list does not give you legally

• No consent to email marketing. Under § 7(2) no. 2 UWG, advertising by email requires the recipient’s prior express consent – towards businesses as well.
• No licence to call. Towards businesses, at least presumed consent is required (§ 7(2) no. 1 UWG); according to the data protection authorities, a general connection to the recipient’s business is not enough.
• No relief under data protection law. If you use personal data from a list, you are the controller for that use: with your own legal basis, the duty to inform under Art. 14 GDPR and the obligation to respect objections to direct marketing (Art. 21 GDPR).

The details for each channel are in B2B Cold Outreach in Germany: What § 7 UWG Allows.

Warning signs

• “100 % up to date”, “checked daily”. Companies move, change their names and are struck off. An honest offer names a reference date.
• “Guaranteed GDPR-compliant”. Whether your use is lawful depends on your purpose and your approach. No seller can guarantee that.
• “Opt-in email addresses” without proof. Ask to see to whom, when and for what consent was given.
• Large numbers of employees’ personal email addresses. Ask about the source. Addresses guessed using the pattern firstname.lastname@ are not data, they are assumptions.
• No sample file, no count before purchase. A seller who only shows what will be delivered after payment has a reason for doing so.

When you do not need to buy a list

To check individual business partners, the free joint register portal of the federal states is enough; anyone may inspect it for information purposes through individual retrievals (§ 9(1) HGB). If you only need the municipalities of a federal state, you will find them in the official municipality directory. For some industries there are public specialist registers that are suitable for looking things up – for example for transport companies, insurance intermediaries or energy suppliers. What each of these registers contains and what it is not intended for is described on the industry pages.

How we handle it at b2bkartei.de

b2bkartei.de supplies company data as a one-off export by industry and region. We compile each export per request and have its sources legally reviewed: for that reason we do not yet publish our own company counts or fixed prices per industry, but state scope, data status and price for your specific selection. Which figures we publish and from which source – such as the official number of businesses per industry – is listed under Data inventory.

The nine checks apply to us too. The answers are on Data sources and methodology, Export and sample file and in the overview Company addresses by industry.

Frequently asked questions

Is it legal to buy company addresses in Germany?

Buying a list of company details is not prohibited. If it includes sole traders, freelancers or named individuals, both seller and buyer are processing personal data and each needs a legal basis under the GDPR. What also matters is what you do with the addresses: § 7 UWG governs how you may contact them.

What is the difference between buying and renting addresses?

When you buy, you receive a file for your own repeated use within the agreed scope. When you rent, use is limited to a set number of mailings or a period of time; often the addresses are not sent to you at all, but to a mailing service provider. Read the terms of use before you compare prices.

Can I get company addresses for free?

You can look up individual companies free of charge in the federal states’ joint register portal, and the Federal Statistical Office publishes, for example, a directory of all municipalities. None of these official sources provides a complete list with contact details that can be filtered by industry and region.

How do I recognise a reputable offer?

The provider names its sources and data status, shows a sample file, confirms the number of records for your selection before you buy and makes no promises that nobody can keep – such as “100 % up to date” or “legally safe for email marketing”.

May I use purchased email addresses for a newsletter?

Only with every recipient’s prior express consent given to you as the advertiser (§ 7(2) no. 2 UWG). A purchased list does not include that consent.

As of 11 October 2026. This article provides general guidance and does not replace legal advice.