# What is ePostman

URL: https://postman.slovakodata.com/help/en/zaciname/co-je-epostman/
Updated: 2026-10-04

The Peppol network, our Access Point role, and reporting invoices to the tax authority — explained simply.

ePostman is a service through which your company sends and receives
electronic invoices. Instead of a PDF attached to an email, the
invoice travels over a secure European network straight into your
business partner's system.

You can send an invoice from your own accounting system or issue it directly
in the portal — see [Issuing an invoice in the
portal](/help/en/portal/vystavenie-faktury/).

### What is Peppol

Peppol is a pan-European network for exchanging business documents,
invoices above all. It works like a postal network: every company
connects to it through a single access point, and those access points
deliver documents to each other in one shared format — regardless of
which accounting system the partner uses.

### What is an Access Point

An Access Point is a provider that technically connects a company to
the Peppol network — it receives that company's documents and
delivers them to the partner's Access Point. ePostman is exactly such
an Access Point. When you send an invoice, we take it from your
system, validate it, and deliver it to your buyer's Access Point,
which then hands it to the buyer.

**C1 through C5.** In Peppol's own documentation, the participants in
this chain are labelled C1 (you, the supplier) through C4 (your
buyer). Slovakia adds a fifth participant — C5, the tax authority, to
whom ePostman reports invoice data. You will not see these
abbreviations anywhere in the portal, but you may come across them in
contracts or technical documentation.

### Why the invoice is reported to the tax authority

Alongside delivering the invoice to the buyer, ePostman also prepares
a **tax data document** (TDD) and sends it to the Slovak tax authority
(FS SR). It is not a copy of the invoice, but a separate data record
carrying its key details, which Slovak law requires for electronic
invoicing. It is sent automatically — you do not have to do anything
extra for it.