In short: A WooCommerce integration with Merit Aktiva or Directo sends orders to accounting as sales invoices with the customer, VAT and payment method, and can bring stock and prices back into the store. Before development, agree when the invoice is created, how returns are handled and which system holds the master product data.
Once a store has more than a couple of orders a day, retyping invoices into the accounting software quickly becomes a time sink and a source of errors. A WooCommerce integration with Merit Aktiva or Directo solves this: orders move from the store to accounting on their own, and stock and prices stay the same in both systems. This guide explains what the integration does, which decisions to make before development and how to avoid the typical mistakes.
What does the integration do?
- Order → sales invoice: a paid order creates a sales invoice in Merit or Directo with lines, prices, discounts, shipping and VAT.
- Customers: new customers are created automatically; existing ones are matched by email or registry code.
- Payments: bank link or card payments are recorded against the invoice, keeping receivables in order.
- Stock: stock levels from accounting or the ERP are updated in the store on a schedule, so the store never sells what is not there.
- Products and prices: if needed, new products and price changes flow from accounting into the store.
Merit Aktiva or Directo?
Both have an API the store can use to send and read data. Merit Aktiva is widely used by small and medium-sized companies and fits well when you mainly need invoices, customers and payments. Directo is a broader ERP, often chosen when warehousing, purchasing, production or several sales channels are more complex. The integration logic is similar; the difference is how much data is synchronised.
Decisions to make before development
- When is the invoice created? On payment, on fulfilment or on shipping. In a prepaid store it is usually on payment.
- Invoice or receipt? Consumers and businesses may need different documents; businesses need their registry code and VAT number.
- VAT: VAT rates and categories must match in the store and in accounting. If you sell to consumers in other EU countries, take the OSS scheme into account.
- Returns: a return or cancellation in the store must create a credit note, not just delete the invoice.
- Where is the master product data? Pick one system as the source of truth for product codes, prices and stock. If both systems change the same data, conflicts follow.
- Product codes (SKU): SKUs in the store and in accounting must match, otherwise lines and stock cannot be linked.
Ready-made plugin or custom integration?
In simple cases a ready-made add-on that sends orders to accounting as invoices is enough. A custom integration makes sense with several warehouses, bundles, customer-specific prices, B2B orders, several stores, or when purchasing and supplier data is needed too. Then we write an integration that follows your exact process and logs every step.
Typical mistakes and how to avoid them
- Duplicate invoices: the same order is sent twice. Fix: every send is recorded and repeats are blocked.
- Silent failures: the API does not respond and nobody notices. Fix: retries, a log and an email alert.
- Rounding differences: totals differ by a cent between store and accounting. Fix: prices and VAT are calculated the same way.
- Stale stock: sync runs rarely and the store sells items that are out of stock. Fix: more frequent sync and a stock buffer for popular items.
What next?
If orders arrive by email or as PDFs rather than through the store, their entry can be automated too – see order processing automation with AI. For a larger process, consider ERP development or business process automation.
IT Solutions builds integrations for new and existing stores – see WooCommerce store development and WooCommerce development.
Frequently asked questions
Can WooCommerce be connected to Merit Aktiva?
Yes. Merit Aktiva has an API through which the store sends orders as sales invoices together with customers and payments. Stock and prices can also flow back into the store.
Can WooCommerce be connected to Directo?
Yes. The Directo API can receive orders and invoices and synchronise products, prices and stock, including across several warehouses.
How often is stock updated?
It depends on the integration and how fast products sell. Usually every few minutes to an hour; fast-selling products deserve more frequent sync.
What happens if the accounting software does not respond?
A good integration retries, logs the error and sends an alert. The order is not lost and is sent once the connection is back.
Can the integration be added to an existing store?
Yes. We start by reviewing the store and accounting setup, check product codes and VAT, and test the integration before it goes live.
Want orders to reach accounting without manual work? Contact us and tell us which software you use.
