Software · By MDJI · Thursday 8 October 2026 · 3 min read

Connecting your website to your accounting: how it works

Orders and payments in your administration automatically. What an integration is, what you need and what to watch out for.

Does an order or appointment come in through your website, and do you then retype it into your accounting? An integration can take over that work. Below you read what an integration is, what you need for it and what to watch out for.

What is an integration?

An integration lets two systems exchange data without anyone retyping it. That happens through an API: a fixed way for other software to talk to a system. Many accounting packages have one, such as Moneybird (Moneybird documentation) and Exact Online. Payment providers such as Mollie also offer an API (Mollie documentation).

What can you connect?

• An order on your website automatically becomes an invoice in your accounting.
• A payment through your payment provider is automatically marked as paid.
• New customers end up in your administration or CRM with their details.
• Appointments from your website end up in your planning or calendar.

What do you need?

1. An overview of your systems: where does data come in, and where does it need to go?
2. A package with an API. Without an API, connecting is difficult or impossible; sometimes it can be done through an export and import.
3. A clear agreement on what is connected: which data, in which direction, and what happens on an error.
4. Access to the systems, with only the permissions the integration really needs.

What to watch out for

• Personal data: an integration often moves customer data. Make sure you know which data ends up where.
• Access keys: the keys the integration logs in with should be stored securely, not in a shared document.
• Errors: what happens if a system is briefly unreachable? A good integration retries and reports it if that fails.
• Changes: suppliers sometimes change their API. An integration then has to change too.

Ready-made or custom?

For many combinations, ready-made integrations or automation services exist. If they do what you need, they are often the fastest route. A custom integration fits if your data flows differently than standard, if several systems are involved at once, or if your website itself has to send the data. In the intake call we first check whether an existing solution is available.

What does an integration cost?

That depends on the systems and what they allow, which is why we do not quote a starting price. After the intake call you receive a proposal with a fixed price. With maintenance, from 50 euros per month, the integration keeps working when a supplier changes something; it is not mandatory.

How we approach it

1. We look at which systems you use and which integration options they offer, before you commit to anything.
2. You receive a proposal with a fixed price, stating which data goes in which direction.
3. We test the integration with test data before real data passes through it.
4. After payment the integration is yours, with all access.

More about integrations and APIs.

Frequently asked questions