Business Central + Salesly Integration: Connect Your ERP and CRM

Companies that work with Microsoft Dynamics 365 Business Central manage accounting, inventory and invoicing in a robust system. But when the sales team needs to track opportunities, send quotes or analyse their sales pipeline, Business Central falls short. That is what a CRM is for.

The problem is that without integration, data lives in two separate systems. The salesperson creates a customer in Salesly, the administrator duplicates it in Business Central. Quotes are generated in the CRM, but invoices are issued from the ERP. Billing data does not reach the sales team, and sales history does not reach accounting.

The integration between Business Central and Salesly eliminates this duplication. A single customer record, a continuous flow from opportunity to invoice, and full visibility for both teams.

Table of Contents

• What syncs between Business Central and Salesly
• How the integration works
• Case 1: Creating a customer from the CRM
• Case 2: From quote to order
• Case 3: Billing visibility in the CRM
• Technical requirements
• What the standard integration does not cover
• When integration makes sense
• Frequently asked questions

Key Points

Point	Details
Bidirectional sync	Contacts, products and orders sync in both directions. A change in Business Central is reflected in Salesly and vice versa.
Duplicate elimination	A customer created in Salesly is automatically created in Business Central. No double manual entry.
Quote to invoice	The complete flow from sales opportunity to issued invoice goes through a single integrated process.
Billing data in the CRM	The sales team sees each customer’s billing status directly in Salesly, without requesting reports from accounting.
Standard REST API	The integration uses Business Central’s REST API (OData v4) and the Salesly API. No proprietary middleware required.

What syncs between Business Central and Salesly

The integration covers four main entities:

Contacts and customers: when a salesperson creates a contact in Salesly and marks them as a customer, a customer record is automatically generated in Business Central with tax details, address and payment terms.

Products and catalogue: the product catalogue is maintained in Business Central (where prices, stock levels and references live) and syncs with Salesly so salespeople can generate quotes with up-to-date data.

Orders: when a quote is accepted in Salesly, it automatically converts into a draft sales order in Business Central. The administrator only needs to validate and invoice.

Invoicing: the invoice status (issued, pending, paid) is reflected in Salesly. The salesperson knows whether their customer has outstanding invoices before making a new offer.

How the integration works

The integration between Salesly and Business Central works through a direct API connection. No CSV files, no manual exports, no third-party middleware.

The technical flow is as follows:

1. Initial setup: both APIs are connected with OAuth 2.0 credentials. Field mapping is defined (which Salesly field corresponds to which Business Central field).

2. Initial sync: existing contacts and products from Business Central are imported into Salesly (or vice versa, depending on which system has the most complete data).

3. Continuous sync: every time a record is created or modified in either system, the change propagates to the other in real time (or at 5-15 minute intervals, depending on configuration).

4. Conflict management: if the same record is modified in both systems simultaneously, a configurable rule applies: “Business Central wins” for accounting data, “Salesly wins” for sales data.

Case 1: Creating a customer from the CRM

Before integration: the salesperson closes a deal in Salesly. They send an email to administration with the new customer’s tax details. Administration opens Business Central, creates the record manually, sets up payment terms and notifies the salesperson. Average time: 24-48 hours.

With integration: the salesperson completes the tax details in the Salesly record (tax ID, company name, registered address, payment terms). On saving, Business Central receives the data and creates the record automatically. Time: immediate.

The net result is that the salesperson can issue the first order on the same day they close the deal, instead of waiting for administration to process the registration.

Case 2: From quote to order

Before: the salesperson generates a quote in Salesly with products and prices. The customer accepts. The salesperson forwards the quote to administration, who re-enters it manually in Business Central as a sales order. Common errors: incorrect prices, unapplied discounts, wrong references.

With integration: the accepted quote in Salesly automatically converts into a draft sales order in Business Central. Products, quantities, prices and discounts transfer without manual intervention. Administration only reviews and confirms.

Transcription errors disappear. The time between acceptance and invoicing drops from days to hours.

Case 3: Billing visibility in the CRM

Before: the salesperson wants to know whether a customer has outstanding invoices before offering them a new service. They call administration, who checks Business Central and responds (if they have time). Or worse: the salesperson does not ask and offers terms to a delinquent customer.

With integration: the customer record in Salesly shows a billing summary: amount invoiced, pending collection, last payment received. The salesperson makes informed decisions without depending on another department.

This visibility changes the dynamic between sales and administration. Fewer interruptions, fewer errors, better commercial risk management.

Technical requirements

To activate the integration you need:

• Business Central: online version (SaaS) or on-premise version with REST API enabled. The cloud version is simpler because the API is enabled by default.

• Salesly: any Salesly plan includes access to the integration API. There is no additional cost for the Business Central connection.

• Permissions: a user with an administrator role in Business Central and integration permissions in Salesly.

• Field mapping: define which fields in each system correspond to each other. Salesly provides a standard mapping template that covers 80% of cases.

• Implementation time: basic setup (contacts + products) is completed in 2-4 hours. Full integration with orders and invoicing requires 1-2 days of technical work.

What the standard integration does not cover

The standard integration syncs contacts, products, orders and invoicing status. But some features fall outside its scope:

• Detailed accounting: journal entries, balance sheets and annual accounts remain exclusively in Business Central. Salesly shows a summary, not the full accounts.

• Real-time inventory management: Salesly shows available stock at the time of sync, but does not manage warehouse movements. Business Central is still needed for that.

• VeriFactu electronic invoicing: electronic invoice issuance under VeriFactu regulations is done from Business Central. Salesly receives the status but does not issue invoices.

• Custom workflows: if your sales process has non-standard steps (multi-level approvals, discounts conditional on annual volume, complex commission rules), custom development may be required.

When integration makes sense

Not every company needs to integrate their ERP with their CRM from day one. Integration makes sense when:

Your sales team has more than 3 people and communication with administration creates bottlenecks. With 1-2 salespeople, an email may suffice. With 5 or more, integration saves hours every week.

You manage more than 50 active customers and double data entry generates recurring errors. Below that volume, the setup effort may not pay off.

Your sales cycle includes formal quotes that later convert into orders. If you sell from a catalogue with fixed prices and no negotiation, quote integration adds less value.

You need cross-functional visibility: the sales team needs to see financial data, or the administrative team needs commercial context to manage incidents.

If your company meets two or more of these criteria, the Business Central + Salesly integration can pay for itself in less than 3 months through administrative time savings alone.

Frequently asked questions

Does the integration work with Business Central on-premise?

Yes, as long as the on-premise version has the REST API enabled (available since Business Central 2019 Wave 2). The connection requires configuring an internet-accessible endpoint or using a VPN. The cloud version (SaaS) is simpler because the API is enabled by default.

What happens if Business Central is down during sync?

Changes are queued and processed automatically when Business Central becomes available again. No data is lost. Salesly retries the sync every 5 minutes for 24 hours before generating an alert.

Can I choose which data gets synced?

Yes. Field mapping is fully configurable. You can sync only contacts, only products, or the full flow. You can also exclude specific fields (for example, sync the customer name and tax ID but not their payment terms).

Does the integration have an additional cost?

The Salesly API is included in all plans. The Business Central connection has no additional cost from Salesly. The only cost is the initial setup time (2-4 hours for basic configuration, 1-2 days for full integration).

Can historical data be synced?

Yes. The initial sync allows importing all existing contacts, products and orders. The process is configurable: you can import only active data or include the full history.