Document classification: how the system determines what is an invoice

How eConnect recognises document types, what is processed and which documents are not accepted as invoices.

When you submit an email with attachments, the system must determine for each attachment what type of document it is. Is it an invoice, a delivery note, a reminder or a logo? This is done via the Detect API, eConnect's entirely proprietary classification technology.

eConnect processes invoices and purchase orders. Documents that are not invoices or orders are automatically filtered. Some are placed as an attachment to an invoice; others are not processed.

How does classification work?

The Detect API analyses each document in two steps:

  1. Visual analysis: a visual fingerprint is created for each document (vector template matching). This is compared to known document templates to recognise the type based on layout.
  2. Text analysis: textual checks are performed via OCR on top of the visual recognition. Based on the combination of visual features and text, a classification decision is made.

Classification is fully automatic. The Detect API is eConnect's own technology, not an external classification service.

Which document types are distinguished?

The system distinguishes the following categories:

CategoryWhat happens to itInvoiceProcessed by the IDR → e-invoicePurchase orderProcessed by the IDR → e-order (beta)Sales orderNot processed as an invoice. The supplier must submit a correct invoice (UBL Invoice).Pro forma invoiceRejected by default. Want a pro forma to be processed? Change the word "pro forma" on the PDF to "invoice" before submitting.Receipt/cash receiptProcessed by the IDR → e-invoice (with dummy values)Delivery notePlaced as an attachment to the invoiceLogoFiltered (image from email signature)PayslipNot processedReminder/payment requestNot processedTax documentNot processedTerms and conditionsPlaced as an attachmentAttachment/specificationPlaced as an attachment to the invoiceUnknownAssessed by the quality team
Which documents do we not process as invoices?
Documents that are not processedDocument typeWhy notWhat you can doSales orderA sales order is an order document from the seller, not an invoice. eConnect does not modify the source document.The supplier submits a correct invoice (UBL Invoice with InvoiceTypeCode 380).Pro forma invoiceA pro forma is not a definitive invoice and has no fiscal status.Submit the final invoice once available.ReminderA reminder refers to a previously sent invoice. Processing would cause a duplicate booking.Submit the original invoice if it has not yet been processed.Payment requestA payment request is legally not an invoice. eConnect processes invoices in accordance with the EU directive.If the document contains an invoice number, date and amount and is issued by a VAT-liable organisation, it may be an invoice. Report it to support for assessment.PayslipNot an invoice. Outside the scope of invoice processing.Cannot be processed via eConnect.Tax documentAssessments, provisional refunds and other tax documents are not invoices.Cannot be processed via eConnect.QuotationA quotation is a proposal, not an invoice.Wait for the final invoice.Documents that are sent as attachments

Non-invoice documents that are in the same email as an invoice are automatically placed as an attachment to that invoice:

  • Delivery notes
  • Specification documents (timesheets, mileage overviews)
  • Terms and conditions
  • Other attachments

This only works if there is also an invoice in the same email.

Logos and images

Images from email signatures (company logos, banners) are automatically recognised as logos and filtered. This prevents a signature logo from being processed as a document.

When is a 'payment request' actually an invoice?

The concept of "invoice" is independent of VAT liability. A document from a non-VAT-liable organisation that charges an amount for services rendered can legally be an invoice, even if the organisation calls it a "payment request". It is about the content, not the label the sender puts on it.

If you think a document has been incorrectly rejected, report this to support.

Classification and rejection

An important distinction: the Detect API classifies documents, but does not reject them itself. The actual rejection of a conversion task is always a manual action by the quality team. A document can be correctly classified as "not an invoice" and then assessed by the team before being rejected.

Reporting classification errors

If an invoice is incorrectly classified as another document type, you can report this to support. The eConnect team can improve the classification so that similar documents are correctly recognised in the future.

Per-sender classification corrections are not possible: classification works generically across all senders. However, the classification model can be extended to recognise specific names (for example if a supplier writes "payment request" but the document is an invoice).

Frequently asked questions
What if my invoice is incorrectly classified as another document type?

Report this to support so that the classification model can be improved. Classification works generically across all senders, but the model can be extended to recognise specific names. The actual rejection is always a manual action by the quality team, not by the Detect API itself.

Does the system automatically recognise attachments to invoices?

Yes, documents such as delivery notes, specifications and terms and conditions that are submitted in the same email as an invoice are automatically placed as an attachment to that invoice.

My supplier submits a sales order instead of an invoice — what now?

A sales order is never recognised or converted as an invoice. eConnect does not modify the source document. The supplier must submit a correct UBL Invoice with InvoiceTypeCode 380.

Can I adjust the classification per supplier?

Per-sender classification corrections are not possible, as classification works generically. However, the classification model can be extended to better recognise specific names. Report this to support.


Has a document been incorrectly rejected? Report it to support so that the classification model can be improved.

Report a classification error