# Overview

URL: https://postman.slovakodata.com/developers/en/uvod/
Updated: 2026-07-24

How an invoice travels from your system to the buyer.

Peppol is a four-corner model. You are the **supplier (C1)** and send the
invoice to us — your **sending Access Point (C2)**. We look up in the SMP
registry which Access Point serves the receiver **(C3)** and deliver the
document over the secure AS4 protocol. That point hands it to the
**buyer (C4)**.

In practice you never deal with certificates, AS4, SMP, or which provider
your buyer uses. You send UBL XML and get a status back.

<dl class="facts">
  <div class="fact">
    <dt>Format</dt>
    <dd>UBL 2.1</dd>
  </div>
  <div class="fact">
    <dt>Profile</dt>
    <dd>BIS 3.0</dd>
  </div>
  <div class="fact">
    <dt>Identifier</dt>
    <dd>0245<small> : DIČ</small></dd>
  </div>
  <div class="fact">
    <dt>Retention</dt>
    <dd>10<small> years</small></dd>
  </div>
</dl>

**Peppol identifier.** Slovak entities are addressed with scheme `0245` and
their tax ID (DIČ) — for example `0245:2020317068`. You pass this value in
the `X-Peppol-Participant-Id` header.