> ## Documentation Index
> Fetch the complete documentation index at: https://docs.invopop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# myDATA supplier registration guide

> Register suppliers with ILYDA to issue invoices through the Greek IAPR's myDATA platform.

## Introduction

The myDATA (My Digital Accounting and Tax Application) platform is Greece’s standardized electronic invoicing and bookkeeping system, managed by the Independent Authority for Public Revenue (IAPR). Invopop has partnered with [ILYDA](https://ilyda.gr) to issue invoices in Greece, and each supplier must be registered with ILYDA before they can issue invoices.

In this guide you'll learn how to register a supplier using the [ILYDA Greece app](/apps/ilyda-greece). Once a supplier is registered, continue with the companion guide: [Greece: Issuing invoices](/guides/gr-iapr).

| -               | Sandbox                                        | Live                                |
| --------------- | ---------------------------------------------- | ----------------------------------- |
| **Supplier**    | Must use test supplier with tax ID `177472438` | Real supplier registration required |
| **Environment** | myDATA test                                    | myDATA production                   |

## Prerequisites

To register a supplier in Greece, you will need:

* Supplier details, including:
  * company name,
  * business activity,
  * VAT number (ΑΦΜ),
  * tax office (ΔΟΥ),
  * full address,
  * phone number and email address, and,
  * legal representative name.
* Access to the supplier's [myTaxisnet](https://www1.gsis.gr/taxisnet/mytaxisnet) account to authorize ILYDA as their e-invoicing provider.

## Setup

Follow these instructions in the [Invopop Console](https://console.invopop.com):

<Steps>
  <Step title="Connect ILYDA Greece App">
    1. Navigate to **Configuration** → **Apps**.
    2. Find **ILYDA Greece** in the app discovery list.
    3. Click **Connect** to activate.

    <Frame>
      <img src="https://mintcdn.com/invopop/-KQ2_uysex-mWyqz/assets/guides/gr-iapr-app.png?fit=max&auto=format&n=-KQ2_uysex-mWyqz&q=85&s=309618a7e5a3a3a9028a08bb3b4cb685" width="400" alt="ILYDA Greece App" data-path="assets/guides/gr-iapr-app.png" />
    </Frame>

    <Info>
      The ILYDA Greece app will send your invoices to the appropriate environment based on whether your current workspace is Sandbox or Live.
    </Info>
  </Step>
</Steps>

## Register a supplier

<Info>
  Supplier registration is only possible in production. In the sandbox environment, your invoices must use a supplier with the tax ID code set to `177472438` which is the TIN of the test supplier pre-enabled in that environment.
</Info>

Invopop has partnered with [ILYDA](https://ilyda.gr) to issue invoices in Greece. Each supplier must be registered with ILYDA before they can issue invoices. The registration process involves providing your company details, authorizing ILYDA as your electronic invoicing provider in TAXIS, and signing a service agreement.

<Info>
  Greek regulation does not allow two myDATA providers to operate simultaneously for the same VAT number. If a supplier currently uses a different provider, they must switch to ILYDA before issuing invoices through Invopop. Switching providers is allowed; the restriction only applies to simultaneous use. See the [Greece FAQ](/faq/greece) for more details.
</Info>

<Warning>
  All communication with ILYDA must go through Invopop. Neither you nor the supplier should contact ILYDA directly at any point during or after the onboarding process. Direct contact can lead to confusion, billing issues, and delays. Always send any questions, documents, or requests to [support@invopop.com](mailto:support@invopop.com).
</Warning>

<Steps>
  <Step title="Supplier authorizes ILYDA as their e-invoicing provider">
    The supplier must authorize ILYDA as their e-invoicing provider in TAXIS:

    1. Go to [myTaxisnet](https://www1.gsis.gr/taxisnet/mytaxisnet) and log in with the company's credentials.
    2. Select the **Authorizations** ("Εξουσιοδοτήσεις") tab on the left sidebar.
    3. Scroll down to the **Providers of E-invoicing** ("Πάροχοι Ηλεκτρονικής Τιμολόγησης") section.
    4. Click **New** ("Νέα").
    5. Enter ILYDA's VAT number: `094359854` and submit the authorization.

    Take note of the date the authorization was submitted — you will need it in the next step.
  </Step>

  <Step title="Send the supplier's details to Invopop">
    Contact [support@invopop.com](mailto:support@invopop.com) with the following information about the supplier you want to register:

    * **Company name**
    * **Business activity**
    * **VAT number** (ΑΦΜ)
    * **Tax office** (ΔΟΥ)
    * **Full address**
    * **Phone number**
    * **Email address**
    * **Legal representative name**
    * **TAXIS authorization date** (from step 1)

    Also specify which document types the supplier needs to issue:

    * **B2B**: invoices issued to private sector businesses.
    * **B2G**: invoices issued to public sector entities.
    * **B2C**: documents issued for individual retail sales.

    If the supplier issues B2C retail sales documents, Greek regulation requires them to have a backup internet service provider (ISP) to ensure uninterrupted connectivity with the e-invoicing platform. You must also provide:

    * **ISP provider name**
    * **Contract number**
    * **Contract date**
  </Step>

  <Step title="Sign the service agreement">
    Invopop will prepare a pre-filled service provision contract with ILYDA based on the details provided in step 2. We can send the contract directly to the supplier or to you as the integrator — let us know your preference. The supplier will have to review the contract, sign it, and return the signed copy to us.
  </Step>

  <Step title="Confirm and go live">
    Once Invopop receives the signed contract, we will complete the onboarding as soon as possible and notify you when the supplier is active and ready to issue invoices.
  </Step>
</Steps>

At this point, you're ready to start sending invoices on behalf of the supplier. Head over to the [myDATA issuing invoices guide](/guides/gr-iapr) to continue.

## FAQ

<AccordionGroup>
  <Accordion title="How do I register a supplier with myDATA?">
    Contact Invopop to begin the onboarding flow with ILYDA. Production registration is multi-step: the supplier authorizes ILYDA in Taxisnet, declares ILYDA as their issuer in myDATA, and signs ILYDA's service agreement, then onboards with Invopop. Sandbox uses a shared pre-registered test AFM (`177472438`) — no manual steps required.
  </Accordion>

  <Accordion title="What credentials does myDATA require to authenticate a supplier?">
    No supplier-side certificates. ILYDA submits to myDATA on the supplier's behalf using its provider credentials, authorized by the supplier through Taxisnet. The supplier holds only their Taxisnet username/password.
  </Accordion>

  <Accordion title="How are supplier credentials stored in Invopop for Greece?">
    Suppliers don't upload credentials to Invopop — ILYDA holds the IAPR submission credentials on the supplier's behalf based on the Taxisnet authorization. Only the AFM and registration metadata are stored in Invopop.
  </Accordion>
</AccordionGroup>

More available in our [Greece FAQ](/faq/greece) section

***

<AccordionGroup>
  <Accordion title="🇬🇷 Invopop resources for Greece">
    |            |                                                                                                                                                                                                                                                   |
    | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
    | Compliance | <Icon icon="https://assets.invopop.com/flags/gr.svg" /> [Invoicing compliance in Greece](/compliance/greece)<br /> <Icon icon="timeline" /> [Compliance timeline](/timelines/greece)                                                              |
    | Apps       | <Icon icon="https://assets.invopop.com/apps/ilyda/icon.svg" /> [ILYDA Greece](/apps/ilyda-greece)                                                                                                                                                 |
    | Guides     | <Icon icon="book" /> [Supplier registration](/guides/gr-iapr-supplier)<br /> <Icon icon="book" /> [Issuing invoices](/guides/gr-iapr)                                                                                                             |
    | FAQ        | <Icon icon="square-question" /> [Greece FAQ](/faq/greece)                                                                                                                                                                                         |
    | GOBL       | <Icon icon="https://assets.invopop.com/icons/gobl.svg" />  [Greece Tax Regime](https://docs.gobl.org/regimes/gr)<br /> <Icon icon="https://assets.invopop.com/icons/gobl.svg" /> [Greece myDATA addon](https://docs.gobl.org/addons/gr-mydata-v1) |
  </Accordion>
</AccordionGroup>

<Card title="Participate in our community" icon="forumbee" href="https://community.invopop.com" arrow="true" horizontal>
  Ask and answer questions about invoicing in Greece →
</Card>