Guide

An e-invoice is an electronic invoice that moves in structured form directly from the sender's system into the recipient's financial management system. For a light entrepreneur, the key point is this: many business customers only accept e-invoices, and with Truster you can send an e-invoice just as easily as a regular invoice, with no invoicing software or operator agreement of your own required.

#What counts as an e-invoice — and what doesn't

With an e-invoice, the invoice data travels in machine-readable, structured form: the amount, due date, reference number and invoice lines are transferred directly into the recipient's system without manual entry. This speeds up invoice processing and reduces errors, which is why businesses prefer e-invoices.

An important clarification: a PDF invoice sent by email is not an e-invoice. A PDF is only an image of the invoice, which the recipient has to process manually or through a separate scanning service. If a customer asks for an e-invoice, a PDF by email won't do. E-invoices travel through the e-invoicing network maintained by operators and banks, not by email.

#When a business customer requires an e-invoice

The larger the organization, the more likely it is to accept only e-invoices. Large companies, municipalities, cities and government organizations have essentially moved to e-invoicing, because they process thousands of invoices and automation saves work. Many small and medium-sized businesses have also switched to digital financial management and prefer to receive e-invoices.

In practice, you'll notice this requirement at the latest when the customer asks about your invoicing method or gives you their invoicing instructions. Always ask for invoicing details before starting the job: that way the invoice goes out in the right format straight away and payment isn't delayed for technical invoicing reasons. If the customer doesn't accept e-invoices, you can send the invoice by email or post instead.

#E-invoice address and intermediary ID

To send an e-invoice, you need two pieces of information from the customer: the e-invoice address and the intermediary ID. The e-invoice address is the company's electronic billing address, typically an OVT identifier or an IBAN-format address. The intermediary ID indicates which operator or bank delivers invoices to that particular company. Together they work a bit like a street address and a postal code: you need both for the invoice to arrive.

The easiest way to get these details is to ask the customer directly, and many companies also publish their invoicing instructions on their websites. Copy the address and intermediary ID carefully: even a single wrong character will prevent the invoice from arriving. Large organizations may have several e-invoice addresses for different units, so make sure you have the right one for your invoice, and ask at the same time for any reference or order number you need to include.

#How to send an e-invoice with Truster

As a light entrepreneur, you don't need to buy invoicing software or sign a contract with an e-invoice operator: Truster handles the e-invoice delivery for you. You create the invoice in the app as usual, choose e-invoice as the delivery method, and enter the e-invoice address and intermediary ID you received from the customer. Truster converts the invoice into the correct e-invoice format and delivers it through the e-invoicing network.

Invoicing costs the same regardless of delivery method: as a light entrepreneur you pay a service fee of 3.99% of invoicing or a flat €55/month. Sending an e-invoice doesn't cost anything extra, so you can also invoice customers who only accept e-invoices.

#Is an e-invoice always the best choice

Whenever a customer can accept an e-invoice, it's almost always the best option. An e-invoice won't get lost in an inbox or caught by a spam filter — it goes straight into the customer's payment processing, and the details arrive error-free. In practice, this means faster payments for you. For consumer customers, invoices are usually delivered by email, since consumers don't have an e-invoice address in the same way businesses do.

In summary: the e-invoice is the standard for business-to-business invoicing, and to send one you need the customer's e-invoice address and intermediary ID. With Truster, you can send e-invoices without any systems of your own, so you can confidently take on jobs from large organizations too.

#The benefits of e-invoicing for light entrepreneurs

The biggest benefit of e-invoicing for you is speed. When an invoice moves directly into the customer's financial management system, it doesn't sit in anyone's inbox or wait in the regular mail: it lands in the customer's processing queue practically the moment it's sent. Within companies, e-invoices also move through approval processes more smoothly than manually entered invoices, since the data is already correctly placed in the system. Faster processing means your invoices get paid on time more often.

A second benefit is reliability. Email can end up in spam, go unnoticed, or reach the wrong person, and a paper invoice can get lost along the way. An e-invoice travels through a closed network straight into the right system, and you're notified if delivery fails. A third benefit is credibility: being able to invoice large organizations the way they require puts you on equal footing with other suppliers. The ability to send an e-invoice can decide whether you get the job at all.

For light entrepreneurs, the barrier to e-invoicing has traditionally been high, because sending e-invoices has required invoicing software and a contract with an e-invoice operator. With Truster, that barrier disappears: you use the same app as always, and the e-invoice is simply one delivery method among others.

#Common problems and how to solve them

The most common e-invoicing problem is an incorrect or outdated e-invoice address. Company addresses change, for example when they switch operators, so don't rely on old information: confirm the address with the customer every time you invoice a new customer or when a long time has passed since your last invoice. If an invoice fails to arrive, first check the address and intermediary ID character by character, and ask the customer whether their details are up to date.

A second typical pitfall is a missing reference. Many large organizations reject or return an invoice if it's missing the orderer's name, an order number, or another reference the customer requires — even if the invoice is otherwise entirely correct. So always ask for invoicing instructions at the start of a job, and enter the required references on the invoice exactly as the customer gave them.

A third situation: the customer doesn't accept e-invoices at all. Not every small business or association has an e-invoice address, and that's not a problem — just send the invoice by email instead. The most important thing is to ask the customer's preferred invoicing method in advance and deliver the invoice in exactly that format. Being flexible about invoicing method is a small effort for you and a big relief for the customer. Once the invoicing method, addresses and references are sorted out on the first invoice, subsequent invoices to the same customer come together instantly: the details are already saved, and you can focus on the work itself instead of sorting out invoicing technicalities.