Exact Online API Integration Services | MG Software B.V.

Exact Online is the most widely adopted cloud ERP platform in the Netherlands and Belgium. Tens of thousands of businesses rely on it for financial administration, project management, inventory tracking and invoicing. Originally built for accountants and SMEs, the platform is now also used by larger organizations as a financial backbone alongside specialized operational software.

What makes Exact Online particularly suitable for integration is its comprehensive REST API. External applications can read from and write to almost every entity in the system: sales orders, purchase invoices, general ledger accounts, project entries and more. The platform also supports webhooks that notify your application immediately when data changes, eliminating the need for continuous polling.

For organizations that operate their own web application, customer portal or online store alongside Exact Online, the need for automated data exchange is almost inevitable. Manually retyping orders, invoices or stock movements is not just time-consuming; it introduces errors that become painfully visible in a financial system. A well-designed API integration solves this by letting data flow in both directions with appropriate validation and error handling.

MG Software has extensive experience building Exact Online integrations across various business processes. We understand the platform's quirks, from division-aware endpoints to its handling of currencies and VAT calculations, and we translate that knowledge into robust connections that run reliably in production environments.

Once an organization grows beyond the point where all employees work directly in Exact Online, data silos emerge. Sales closes a deal in the CRM, operations processes the order in custom software, and finance manually books entries in Exact. Each manual step adds lead time and increases the chance of transcription errors. During month-end close, those errors surface as reconciliation differences that take hours to investigate.

By connecting your operational software directly to Exact Online, these manual steps disappear. Orders created in your own system automatically appear as draft invoices or sales entries in Exact. Stock movements from your warehouse software are written back so that the financial inventory value stays accurate. Payment statuses flow back to your customer portal, allowing clients to check for themselves whether an invoice has been settled.

The benefits extend beyond time savings. Real-time visibility into debtor positions and cash flow enables management to make faster decisions. Finance no longer needs to wait for manual input to update the books. And for compliance purposes, an automated integration provides an auditable trail of every mutation, including timestamps and source attribution.

For businesses in industries where margins are tight, such as wholesale, manufacturing or e-commerce, the difference between a manual and an automated process can directly impact profitability. Every minute spent on data entry is a minute not spent on customer relationships or product development.

Every Exact Online integration begins with authentication. The platform uses OAuth 2.0, which means your application must complete an authorization flow to obtain an access token. This token has a limited lifespan and must be periodically refreshed using a refresh token. We build this token rotation as a background process that runs automatically, ensuring the integration never stalls due to an expired session.

An important technical characteristic of Exact Online is the concept of divisions. Many organizations manage multiple administrations within a single Exact environment, and every API request must specify which division it targets. Our integrations account for this explicitly by treating division mapping as configuration, allowing you to add new administrations later without code changes.

For real-time synchronization we use webhooks wherever available. Exact Online can notify your application when an entity changes, so there is no need to continuously check for updates. For situations where webhooks are not available or not reliable enough, we supplement with scheduled synchronization jobs that run at fixed intervals and apply delta processing.

Every API request is designed to be idempotent. When a request fails to confirm due to a timeout or network disruption, it can safely be retried without creating duplicate entries. We use unique references and pre-checks to prevent duplicates. Additionally, we respect the rate limits that Exact enforces per minute and per day, with automatic throttling and exponential backoff when limits are approached.

Error handling is a foundational part of the architecture. When an API request fails, it is placed in a dead-letter queue with full context: which mutation, which data, which error message. An operator dashboard displays outstanding errors and offers the ability to manually reprocess or dismiss them. Alerts fire when the error count crosses a threshold, ensuring your team can intervene quickly.

Financial data is among the most sensitive categories within any organization. The API integration with Exact Online processes invoices, amounts, account numbers and potentially debtor information. For this reason we adopt a security-first approach in every design decision.

OAuth tokens are stored encrypted and never logged. Refresh tokens rotate automatically and are invalidated after use. All communication runs over TLS and we validate certificates to prevent interception. For applications running in cloud environments we use managed secret stores rather than configuration files.

We also build audit trails for every mutation that passes through the API. Each request is logged with a timestamp, the trigger source and a reference to the originating business event. This makes it possible during an audit to trace exactly how a booking was created, which system initiated it and whether any manual corrections were applied.

One of the most common challenges in Exact Online integrations is working with multiple administrations. Organizations that manage several legal entities or branches in separate divisions run into the fact that every API call must explicitly specify which division it targets. Mistakes in division mapping can cause bookings to land in the wrong administration, which is difficult to reverse.

A second challenge is the complexity of general ledger mapping. Businesses use varying chart-of-accounts structures and the way a sales order translates into journal lines differs from one organization to the next. Configuring this mapping correctly requires close collaboration between your finance team and our developers.

Finally, many teams discover that Exact Online's rate limits are more restrictive than expected, especially during bulk operations like importing historical data. Our approach is to schedule bulk imports during off-peak hours, batch requests where the API allows it, and use a queue mechanism that automatically throttles when limits are reached.

After go-live we actively monitor the integration during an onboarding period. Error rates, processing times and queue depths are tracked in a dashboard your team can access. Alerts are configured for scenarios requiring immediate action, such as a persistent authentication failure or an unexpectedly high error rate.

Exact Online regularly updates their API. New versions or deprecated endpoints are handled by building the integration with an abstraction layer that isolates changes. Periodically we review the Exact Online release notes and plan any necessary adjustments as part of regular maintenance.

The investment for an Exact Online integration depends on the number of entities involved, the complexity of your business logic and the availability of a test environment. A first production integration with a single bounded flow, for example orders to invoices, typically fits within a scope of a few sprints.

For organizations with multiple administrations, complex ledger mapping or high transaction volumes, we recommend a phased approach where each phase delivers a working and testable result. This avoids a long engagement without intermediate value.

We work with fixed sprint budgets and transparent time tracking. A no-obligation scoping conversation gives you a clear picture of the expected investment before you commit.