Connect my Sellsy account

Prerequisites

Before starting, make sure that:

• You are the administrator of your Sellsy account
• You have an active API access (or an OAuth connection if enabled)
• You are logged in to your Fincome account
• You have access to the Customers, Products, Invoices, Credit notes modules in Sellsy

Overview of the integration

The Sellsy integration allows automatic synchronization of the following entities:

• Customers (companies)
• Products & Prices
• Invoices
• Credit notes (refund notes)

Fincome transforms this data to produce useful financial metrics, even in the absence of subscriptions:

• Monthly net revenue
• Analysis of discounts
• Net / Gross comparison
• Tracking payments in multiple currencies
• Customer billing cohorts

Integration steps

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1. Connect to Sellsy from Fincome

1. Log in to your Fincome space
2. Go to the Data tab in Settings
3. Click on Connect a new billing system

1. Select Sellsy from the list
2. Follow the OAuth instructions (or enter your API credentials if necessary)

Once access is validated, the initial synchronization starts automatically.

Verify the integration

1. Go to the Sources tab in Fincome
2. Check the status of the last synchronization
3. View the Customers, Revenue, Documents views
4. The data should be present, with your invoices and credit notes

Updated on: 01/06/2026