The Open-Source B2B CRM Built for Complex Sales

What is a B2B CRM and why does your team need one?

A B2B CRM (business-to-business customer relationship management) is software designed to help companies that sell to other companies manage accounts, track deals across longer sales cycles, and coordinate multi-stakeholder relationships. Unlike a B2C CRM that handles high-volume, short-cycle transactions, a B2B CRM system focuses on fewer deals with higher value and more complex buying committees.

If your sales team juggles spreadsheets, loses follow-ups in email threads, or cannot tell you what the open pipeline is worth, you need a proper CRM for B2B. Customermates is an open-source, AI-native B2B CRM made in Germany, with organizations, multi-contact deals, a weighted pipeline, and an API and MCP server for automation and AI clients.

Why B2B sales are different and why generic CRMs fail

B2B selling is different from B2C, and a CRM that ignores those differences creates more friction than it removes. Here is what makes B2B unique:

Longer sales cycles

Deals take weeks, months, or even quarters to close. Your CRM needs to keep the history of every touchpoint across that timeline (emails, calls, meetings, proposals) so nothing falls through the cracks. Customermates gives you a pipeline view that maps every deal stage from initial outreach to signed contract, and an activity history on every record.

Multiple stakeholders per deal

In B2B, you rarely sell to one person. A typical deal involves procurement, technical evaluators, department heads, and C-level sponsors. Customermates lets you link multiple contacts to a single deal and organization, and a custom field can record each contact's role. Use contact management to keep every stakeholder relationship.

Account-based selling and company structures

B2B CRM software must support account-based selling, focusing sales efforts on target accounts rather than individual leads. Customermates holds each company as an organization with its contacts and deals (see account management). There are no built-in parent and subsidiary hierarchies; record the parent company or division in a custom field and group or filter by it.

Higher deal values and complex negotiations

When deals are worth five or six figures, every detail matters. Typed custom fields let you track contract terms, procurement requirements, competitor activity, and technical specifications alongside the standard deal data.

Integration with business tools

B2B companies rely on ERP systems, accounting software, marketing tools, and project management tools. A disconnected CRM becomes a data silo. Customermates connects to your existing stack through a REST API and webhooks, and n8n, operated separately, connects through the Customermates community node.

How Customermates works as your B2B CRM

Customermates maps your business-to-business sales process, from the first touch to close and long-term account management.

Pipeline management with custom deal stages

Define deal stages that match your B2B sales process: qualification, discovery, proposal, negotiation, legal review, closed-won. The pipeline Kanban view lets you drag deals between stages and spot stalled deals. Each stage carries a probability, so you get weighted deal values and weighted pipeline totals. That is a deterministic calculation from your own stage weights, not a predictive forecast.

Lead qualification

Not every inbound inquiry is worth your team's time. With lead management, you track leads as contacts and early-stage deals and record qualification criteria such as company size, industry, budget, and timeline in custom fields. There is no automatic lead scoring or routing; saved views filtered by your criteria show which leads to work next.

Organizations and contacts with full relationship mapping

In B2B, you sell to companies, not individuals. Customermates links contacts to organizations so you see who belongs to which company, what deals are active, and the interaction history, tasks, notes, and activity in one place.

Unified inbox and communication tracking

On Pro and above, email, LinkedIn, WhatsApp, Instagram, and Telegram come together in one unified inbox, and you link each conversation to the right contact and share individual conversations with your team, which matters when multiple reps touch the same account. Sharing whole connected accounts and the team-wide timeline are on Business. The Mate assistant can draft replies, and it asks for confirmation before anything is sent.

Automation with webhooks, REST and n8n

Customermates has no built-in workflow builder. It emits webhooks and exposes a REST API, so an external tool such as n8n (operated separately) can:

• Create tasks when a deal moves to a new stage
• Flag deals that have had no activity for a set number of days
• Notify your team in Slack or Microsoft Teams when a high-value deal progresses
• Sync data between Customermates and your ERP, accounting, or marketing tools

On Customermates Cloud, routines also let the Mate assistant run a saved prompt on a schedule or on a CRM event.

Reporting and sales analytics

Build reporting dashboards from your own records: open pipeline by stage, weighted pipeline totals, deal values by owner, and win and loss counts. Leadership sees pipeline health without waiting for weekly status meetings.

AI clients that operate your CRM

Connect Claude, ChatGPT, or another AI client through the MCP server (50 tools) and let it do the data entry: log activity, move deals between stages, draft personalized outreach, and summarize lengthy deal histories. You choose and pay for the AI client. The pipeline stays current and reps spend less time on manual updates.

B2B CRM vs. B2C CRM: key differences

Understanding the distinction helps you choose the right tool:

Customermates is built for the left column. If your sales process involves account-based selling, multi-stakeholder negotiations, and deal cycles measured in weeks rather than minutes, it fits.

Deal stages for B2B sales: a practical framework

Most B2B companies benefit from pipeline stages that reflect the actual buying journey:

1. Lead qualified: The prospect matches your ideal customer profile and has expressed interest.
2. Discovery: You have scheduled a first meeting to understand the prospect's needs, budget, and timeline.
3. Proposal sent: A formal proposal or quote has been delivered.
4. Negotiation: Terms, pricing, or scope are being discussed with procurement or leadership.
5. Legal / contract review: The deal is in the hands of legal teams on both sides.
6. Closed-won: Contract signed, deal closed, onboarding begins.
7. Closed-lost: The deal did not close. Record the reason to improve future efforts.

Customermates lets you customize these stages entirely. Add, rename, or reorder them to match your B2B sales process.

Integrations that matter for B2B companies

A B2B CRM does not exist in isolation. Customermates connects with the tools your business already relies on through the REST API, webhooks, and n8n:

• ERP systems: Sync customer data and order history between your CRM and ERP through an integration you build
• Accounting software: Pass won deals to your invoicing tool; Customermates does not create invoices
• Marketing tools: Push qualified leads from campaigns into your pipeline through the API
• Email: Connect Gmail, Outlook, or IMAP mailboxes to the unified inbox on Pro and above
• Team chat: Send deal updates to Slack or Microsoft Teams through n8n; there is no native Slack integration
• Calendar: Read-only calendar access on Pro and above; Customermates does not book meetings

There are no proprietary connectors and no integration fees; you build and run the workflows.

Pricing that works for B2B teams

With many CRM vendors, costs escalate with every feature, every user, and every integration. Customermates takes a different approach:

• Starter (€12 per user per month): pipeline, custom fields, views, dashboards, REST, webhooks, and MCP
• Pro (€29 per user per month): adds the unified inbox for email, LinkedIn, WhatsApp, Instagram, and Telegram
• Open source: full transparency; records can be taken out through the REST API and XLSX export (one record type at a time)
• Data protection: cloud database in the AWS Frankfurt region, DPA available, subprocessors disclosed
• Self-hostable: deploy the open-source core on your own infrastructure at no licence cost; the inbox and Mate are cloud-only

Multi-stakeholder outreach runs through email and LinkedIn, so most B2B teams land on Pro. For a B2B sales team of 10, that is €290 per month. Compare that total directly with Salesforce, HubSpot, or Dynamics 365 quotes; editions and add-ons determine the exact difference.

Getting started with Customermates as your B2B CRM

Setting up your B2B CRM:

1. Create an account: no credit card required. Your first 7 days are free.
2. Import your data: from an Excel workbook (XLSX), one record type at a time, or through the REST API. There is no CSV import.
3. Configure your pipeline: define B2B-specific deal stages and custom fields for your sales process.
4. Invite your team: add colleagues and assign roles and permissions.
5. Connect automations: through webhooks, n8n, or cloud routines, if you need them.
6. Connect your channels: on Pro, link your mailboxes and LinkedIn to the unified inbox.

Customermates is open source and self-hostable. That means full code transparency and a CRM whose code you can inspect and run yourself; records can be taken out through the REST API and XLSX export (one record type at a time).

Frequently asked questions about B2B CRM