Selling on several European marketplaces is one of the fastest ways to grow an eCommerce business. It is also one of the fastest ways to overload the admin team. Every Amazon, eBay or Allegro order generates an invoice, a payment, a fee and sometimes a return. When all of that is handled by hand, invoicing becomes the bottleneck that limits growth. In this article we explain why it happens, what can be automated with an ERP and how to approach it without breaking your accounts.
The hidden cost of invoicing marketplace orders by hand
With a single sales channel, issuing invoices for orders is one more task in the week. With four channels, customers in several countries and hundreds of orders a month, it becomes a full-time job. Worse, that work grows at exactly the same pace as sales: the better the marketplaces perform, the more hours admin needs to keep up.
Time is not the only cost. Manual marketplace invoicing is a constant source of errors: incomplete tax details, wrong VAT rates, gaps in numbering, duplicated invoices or invoices that are never issued. Each error then creates more work in reconciliation, at month-end and, in the worst case, during a tax inspection. It is a cost that doesn't appear on any line of the P&L, but it is paid every week.
Why marketplaces complicate invoicing
Every marketplace delivers order information in its own way. Some include the buyer's tax details and others don't. Some settle payments by period, with fees already deducted, and others order by order. Returns and partial refunds are reported in different formats and at different times. None of this fits naturally into invoicing software designed for your own store.
On top of that comes European taxation. Since July 2021, distance sales to consumers in other EU countries are taxed at destination once the common threshold of €10,000 a year is exceeded, and VAT is declared through the One-Stop Shop, known as OSS. In practice, that means applying the buyer's country VAT rate on every invoice. Without a system that does it automatically, every international order means checking by hand which tax applies.
What can be automated in eCommerce invoicing
Practically the whole journey, from the moment the order comes in until it is recorded in the accounts. The goal is not to remove people from the process, but for them to step in only on exceptions. A well-automated invoicing flow covers at least these steps:
- Automatic import of each channel's orders into the ERP
- Invoice created from the order, with no copying of data
- Automatic completion of the customer's tax details
- The correct VAT applied according to the delivery country
- Credit notes generated for returns and refunds
- Reconciliation of each marketplace's settlements with its fees
When these steps run on their own, admin work changes completely. Instead of issuing invoices, the team reviews the cases the system flags as doubtful and spends the rest of its time on higher-value tasks, such as controlling margins by channel.
Start with the process, not the tool
The most common mistake is to start configuring automations without first understanding how each order arrives and what information it carries. Automating a poorly defined process only means making the same mistakes faster. That's why the first step is always to analyse the real flow: where each order comes from, what data is missing to invoice it correctly and at which point it gets lost.
That is how we approached ADDITEQ, an international eCommerce business selling through its own online store and several European marketplaces, including Amazon, eBay and Allegro, with a catalogue in several languages. Before touching the configuration, we analysed how each channel's orders were generated and invoiced. With that information we configured Odoo to create invoices for marketplace orders automatically and to complete the invoicing details with no manual intervention.
The ERP as the core of invoicing
The reason an ERP solves this problem is simple: it brings orders, customers, products, taxes and accounting into one system. When everything lives in the same place, the invoice stops being a separate task and becomes an automatic consequence of the order. And the accounting entry, in turn, an automatic consequence of the invoice.
Odoo is a common choice in eCommerce and distribution because it integrates sales, invoicing and accounting on a single platform and has connectors for the main marketplaces. But the principle is the same with any well-implemented ERP: one source of truth so that tax and accounting information is consistent across every channel. The tool matters less than the process designed on top of it.
Common mistakes when automating invoicing
The first is automating without cleaning the data first. If customer records, products or taxes are badly configured, automation multiplies the error on every order. The second is treating every marketplace the same, when each has its own logic for settlements, fees and returns.
The third is forgetting returns and refunds, which is precisely where an eCommerce business's accounts most often stop adding up. And the fourth is leaving no controls. Good automation is not a black box: it includes alerts for orders that don't fit the rules and lets you check at any time what the system did and why.
How to measure the impact of automation
Before automating, it is worth measuring how much time the team spends invoicing today, how many invoices need correcting each month and how long the month-end close takes. They are three simple indicators that let you compare before and after with data, not impressions.
What changes when invoicing runs on its own
The most visible change is time: the team stops copying data from one system to another. But the most important one is consistency. The information for each order is the same in the sales channel, the ERP and the accounts, and month-end speeds up because invoices and payments are already recorded and reconciled.
Above all, invoicing stops being a limit on growth. Opening a new marketplace or starting to sell in a new country no longer means hiring someone else to invoice, but configuring one more channel in a process that already works. In the projects we have supported, it is one of the changes with the biggest day-to-day impact for a multichannel eCommerce business. If you want to know which part of your invoicing can be automated, an Operations Assessment is the best starting point.