E-invoicing and digital accounting documents: order in incoming invoices

Order in incoming invoices means two things: the accounting documents themselves run cleanly through accounting and the ERP – and the knowledge around the documents can be found, from the contract behind the invoice to the instructions on how incoming invoices are handled. E-invoicing makes this separation more important, because invoices will arrive through more channels and in more formats. This guide sorts out what belongs where – and where an AI knowledge base helps without replacing accounting.

In brief

• An e-invoice in the narrower sense is an invoice in a structured, machine-readable format – for VAT purposes in Austria, however, a PDF sent by email also counts as an electronic invoice (Section 11(2) of the Austrian VAT Act, UStG); structured formats only become mandatory EU-wide with ViDA (the EU’s “VAT in the Digital Age” package).
• For accounting documents, accounting together with the ERP remains the leading system; even the best knowledge base does not change that.
• In Austria, books and accounting documents must generally be kept for seven years – accounting and your tax adviser are responsible for this.
• The ERP knows what was booked – the knowledge base knows what lies behind it: contracts, arrangements, processes.
• Order comes from one clear incoming channel, fixed responsibilities and a documented process that the person covering can also read up on.

What does e-invoicing change for incoming invoices?

An e-invoice is an invoice in a structured electronic format: the invoice data is available in such a way that software can process it directly without retyping. This distinguishes it from a PDF sent by email – which is digital, but only an image of the invoice, from which a person or text recognition first has to read out the data.

In Austria, e-invoicing has been mandatory for suppliers to federal government bodies for years, and at EU level the gradual extension of structured invoice formats is mapped out. The current status for your industry and situation is provided by the information pages of the Austrian Economic Chamber (WKO).

In practice, this means one thing above all for the coming years: coexistence. Paper, PDF and structured formats arrive in parallel – by post, via several inboxes and through portals. It is precisely this coexistence that makes order in incoming invoices more important than ever: many channels, but one process.

Who keeps the accounting documents – accounting or the knowledge base?

The answer is clear and should stay that way: accounting, with its ERP or accounting system, is the leading system for accounting documents. Capturing, checking, booking and archiving invoices is its task – that is where the documents belong, and that is where they are kept.

This also includes statutory retention: in Austria, books and accounting documents must generally be kept for seven years, longer in certain cases; the relevant law is the Federal Fiscal Code (Bundesabgabenordnung, BAO), available in the federal legal information system RIS. Clarify the details with your tax adviser – this article is not tax or legal advice.

An AI knowledge base is expressly not an archive of accounting documents for tax purposes and does not want to be one. Anyone who keeps accounting documents twice creates confusion instead of order. The clean rule is: one truth per purpose – the accounting document in the ERP, the knowledge about it in the knowledge base.

What knowledge around the invoice is missing from the ERP?

The ERP reliably answers what was booked, when and with what status. But it is silent on the why and how: which maintenance contract is behind the monthly invoice? What was agreed with the supplier on charging for call-out trips? Why was an item disputed last year, and how did the matter end?

Then there is the instructional knowledge that is not in any system: how do we handle incoming invoices? Who checks the content, who approves, in what order? What do we do with an invoice that has no purchase order reference? Processes like these usually sit in the head of a single person – until that person is on holiday and the person covering is left guessing.

Another typical case is the query from the tax adviser months later: what does this incoming invoice relate to, was it a repair or an acquisition, is there a contract for it? The business knows the answer – it is just in an email from the spring that someone first has to find. Documented background knowledge turns such searches into a two-minute query.

It is exactly this background knowledge that belongs in the knowledge base: queryable in plain language, with a source pointing to the document. The person covering asks “What did we agree with the maintenance provider on billing?” and receives the answer from the framework contract – with the source, so it can be read in the original.

What belongs where? The distinction at a glance

Task or content	Leading system
Capture, check, book invoices	Accounting / ERP
Retention of accounting documents for tax purposes	Accounting / tax adviser
Payment status and open items	ERP
Framework contracts and agreements on terms	Knowledge base
Correspondence on disputed invoices	Knowledge base
Instructions “How we handle incoming invoices”	Knowledge base
Decisions on special cases, including reasons	Knowledge base

A rule of thumb that has proved its worth: the ERP knows what happened – the knowledge base knows how it is done and why it was done that way. If you ask yourself this question for every document, you sort it correctly almost automatically.

The separation has a second advantage: it keeps both systems lean. Accounting is not burdened with correspondence and instructions that nobody looks for there – and the knowledge base stays free of piles of accounting documents that have no business being there. Each system does what it does best.

How do you bring order to incoming invoices?

1. Define one incoming channel: A dedicated email address for invoices instead of receipt via five personal inboxes – paper post is scanned and put into the same channel.
2. Name responsibility and cover: One person is responsible for incoming invoices, a second can take over – and, thanks to documentation, also knows how.
3. Document the process properly once: From receipt through checking the content to approval. These instructions are themselves a core part of the knowledge base – they make the process independent of individual people.
4. Link the knowledge: File framework contracts, agreements and documented special cases centrally and make them queryable, so that nobody has to dig through inboxes when questions arise.
5. Test with the person covering: The person covering answers typical questions using only the knowledge base – every gap is documented and closed.

How such processes work permanently in the business – with routines that still hold after the first month – is shown in the practical guide to the AI knowledge base.

Where are the limits – and how do you start?

Honesty includes three limits: the knowledge base replaces neither accounting software nor your tax adviser, and it does not automate invoice approval either – there are dedicated tools for that. It supplies the knowledge about the process, not the process itself. And because AI can make mistakes, every answer names the source document – before making decisions, a look at the original is part of it.

Getting started is manageable: the process instructions can be written in half a day, and the most important framework contracts are quickly collected. How this becomes a queryable knowledge base is shown step by step in the introduction process.