# Novus Conceptus developer documentation

> Novus Conceptus is a certified e-invoicing provider in Greece (AADE provider code 005). This is the complete documentation of the Provider API (issuing invoices, receipts, delivery notes and B2G invoices through myDATA) and the Onboarding API (activating clients), with the AADE code tables, ready-made JSON examples and the FAQ.

- Sandbox base URL: https://provider-dev.timologisi.online (free account by registration). Production: https://provider.timologisi.online (after certification).
- Every call sends the API key in the HTTP header `API-KEY`. One key serves all the issuer VAT numbers of the account.
- `SendInvoices` takes exactly one document per call and returns MARK, UID, Authentication Code and the PDF link in the same response.
- Full text of every page in one file: https://developers.novusconceptus.com/llms-full.txt
- Greek version: https://developers.novusconceptus.com/el/llms.txt and https://developers.novusconceptus.com/el/llms-full.txt
- OpenAPI (YAML) and Postman collections: https://developers.novusconceptus.com/tools/

## Home

- [Certified e-invoicing provider API for Greece](https://developers.novusconceptus.com/): E-invoicing API for Greece from a certified AADE provider. Send invoices and receipts as JSON, get the myDATA MARK, a PDF with QR code and email delivery.

## Getting started

- [How it works](https://developers.novusconceptus.com/start/how-it-works/): How the Novus e-invoicing API works: your app sends JSON, the provider transmits it to AADE myDATA and returns MARK, UID, Authentication Code and a PDF.
- [Environments & API key](https://developers.novusconceptus.com/start/account/): Sandbox and production environments of the Novus e-invoicing API for Greece: sign-up, API-KEY header authentication, base URLs and technical requirements.
- [Your first document](https://developers.novusconceptus.com/start/first-invoice/): Issue your first retail receipt (11.1) in the sandbox: a ready-made JSON for SendInvoices, cURL, C#, Delphi and Python code, and the myDATA MARK response.
- [Certification & going live](https://developers.novusconceptus.com/start/go-live/): Certification and go-live for the Novus e-invoicing API: run the core myDATA scenarios, apply online, get a production key and activate customer VAT numbers.

## Guides

- [Invoices & receipts](https://developers.novusconceptus.com/guides/invoices/): Issue invoices and retail receipts through the myDATA e-invoicing API in Greece: choose the AADE document type, classify income and send ready JSON examples.
- [Credit notes & correlations](https://developers.novusconceptus.com/guides/credit-notes/): Issue credit notes 5.1, 5.2 and 11.4 to myDATA via the e-invoicing API: correlated invoices, reversing a document and ready JSON examples for AADE in Greece.
- [Taxes, fees, deductions](https://developers.novusconceptus.com/guides/taxes/): How to send withholding tax, fees, other taxes, digital transaction fee and deductions to myDATA — per line or with taxesTotals, with JSON examples.
- [Card / IRIS payments](https://developers.novusconceptus.com/guides/card-payments/): Card and IRIS payments with a provider signature for POS terminals linked to myDATA (A.1155/2023): NSP integration, completion, testing and failed payments.
- [Food service: order slip 8.6](https://developers.novusconceptus.com/guides/food-service/): Food service order slips (8.6) in myDATA via the e-invoicing API: table orders, item cancellations, closing the table and the 24-hour rule in Greece.
- [Goods movement: delivery notes](https://developers.novusconceptus.com/guides/delivery/): Send delivery notes to myDATA via the e-invoicing API: invoice as delivery note, standalone 9.3, myDATA 2.0 digital delivery note fields and cancellation.
- [Public sector (B2G)](https://developers.novusconceptus.com/guides/b2g/): How to send B2G e-invoices to Greek public sector bodies (EN 16931) with the e-invoicing API — routing fields, CPV codes, sandbox test values, JSON examples.
- [OSS: sales to consumers in the EU](https://developers.novusconceptus.com/guides/oss/): How to report EU One Stop Shop (OSS) distance sales to consumers in myDATA — VAT exemption category 30, two-line retail receipt and a JSON example.
- [Offline & retries](https://developers.novusconceptus.com/guides/offline/): What to do when the connection to the e-invoicing provider or AADE myDATA drops: retries, transmissionFailure 1 and 2, error 228 and when to resend a document.

## Provider API

- [Provider API](https://developers.novusconceptus.com/provider-api/): Provider API reference for issuing invoices and transmitting them to AADE myDATA (2.0.2) in Greece — base URLs, API key authentication and all endpoints.
- [SendInvoices](https://developers.novusconceptus.com/provider-api/send-invoices/): SendInvoices field reference for the Greek e-invoicing API. Issue a document, transmit it to AADE myDATA, and get the MARK, UID and PDF back.
- [SendInvoicesB2G](https://developers.novusconceptus.com/provider-api/send-invoices-b2g/): SendInvoicesB2G endpoint for B2G e-invoices to Greek public sector bodies (EN 16931) — allowed types, required fields, BT codes, credits and sandbox testing.
- [Other endpoints](https://developers.novusconceptus.com/provider-api/other-endpoints/): Other Provider API endpoints for myDATA e-invoicing in Greece — search issued documents, cancel delivery notes, credits balance, public PDFs and POS payments.
- [Errors & statusCode](https://developers.novusconceptus.com/provider-api/errors/): How to handle errors in the myDATA e-invoicing API — HTTP status codes, statusCode values, AADE validation errors, Offline documents and safe retries.
- [AADE error codes](https://developers.novusconceptus.com/provider-api/aade-errors/): Every AADE myDATA error code a document sent through the e-invoicing provider can return, with the exact English message and what it means.
- [Charges (credits)](https://developers.novusconceptus.com/provider-api/credits/): Credits pricing for the myDATA e-invoicing API in Greece — cost per call and document type (invoices, receipts, B2G, POS) and how to check your balance.

## Onboarding API

- [Onboarding API: how it works](https://developers.novusconceptus.com/onboarding-api/): How the Novus Onboarding API activates client VAT numbers on your API key in Greece, from contract signing and review to the AADE Provider declaration.
- [Onboarding API: endpoints](https://developers.novusconceptus.com/onboarding-api/endpoints/): Reference for Novus Onboarding API endpoints that onboard client VAT numbers for e-invoicing in Greece, with request fields, contract upload and error codes.
- [Webhooks](https://developers.novusconceptus.com/onboarding-api/webhooks/): Receive real-time webhooks from the Novus Onboarding API when a client onboarding request changes, with retries and HMAC-SHA256 signature verification.

## AADE code tables

- [AADE code tables](https://developers.novusconceptus.com/aade/): All AADE myDATA 2.0.2 code tables for Greek e-invoicing: document types, VAT, taxes, classifications, payments, goods movement.
- [Document types](https://developers.novusconceptus.com/aade/documents/): AADE myDATA 2.0.2 code tables: Document types. Every code with its description, as you send it to the Novus Conceptus e-invoicing API.
- [VAT](https://developers.novusconceptus.com/aade/vat/): AADE myDATA 2.0.2 code tables: VAT. Every code with its description, as you send it to the Novus Conceptus e-invoicing API.
- [Taxes, fees, deductions](https://developers.novusconceptus.com/aade/taxes/): AADE myDATA 2.0.2 code tables: Taxes, fees, deductions. Every code with its description, as you send it to the Novus Conceptus e-invoicing API.
- [Income & expense classifications](https://developers.novusconceptus.com/aade/classifications/): AADE myDATA 2.0.2 code tables: Income & expense classifications. Every code with its description, as you send it to the Novus Conceptus e-invoicing API.
- [Lines & payments](https://developers.novusconceptus.com/aade/lines-payments/): AADE myDATA 2.0.2 code tables: Lines & payments. Every code with its description, as you send it to the Novus Conceptus e-invoicing API.
- [Goods movement](https://developers.novusconceptus.com/aade/movement/): AADE myDATA 2.0.2 code tables: Goods movement. Every code with its description, as you send it to the Novus Conceptus e-invoicing API.

## Postman & examples

- [Postman & examples](https://developers.novusconceptus.com/tools/): Postman collections, OpenAPI (YAML) files and 32 ready-made JSON examples for the myDATA e-invoicing API: invoices, receipts, POS, food service, delivery, B2G.

## FAQ

- [FAQ](https://developers.novusconceptus.com/faq/): FAQ for developers integrating the Novus e-invoicing API in Greece, covering myDATA, AADE, client onboarding, invoices, credit notes, errors and card payments.
- [Getting started & account](https://developers.novusconceptus.com/faq/start/): Getting started with the Novus e-invoicing API for Greece, covering sandbox access, API keys, many client VAT numbers on one key, archiving and credits.
- [Certification & production](https://developers.novusconceptus.com/faq/go-live/): How certification works for the Novus e-invoicing API in Greece, from the sandbox test scenarios to your production API key, plus B2B and B2C coverage.
- [Onboarding & clients](https://developers.novusconceptus.com/faq/onboarding/): FAQ on onboarding clients to the Novus e-invoicing API for Greece: Onboarding API requests, contracts, myAADE authorization and Provider declaration to AADE.
- [Issuing documents](https://developers.novusconceptus.com/faq/invoices/): FAQ on issuing invoices and receipts with the Novus e-invoicing API for Greece: SendInvoices response, numbering, income classification, PDF and email.
- [Credit notes & cancellations](https://developers.novusconceptus.com/faq/credit-notes/): How to cancel a document in myDATA with the Novus e-invoicing API: a retail receipt with an 11.4, a wholesale invoice with a 5.1 or 5.2, self-billing and correlation.
- [Errors](https://developers.novusconceptus.com/faq/errors/): Common Novus e-invoicing API errors for Greece explained: HTTP 401 and 400, Offline status, AADE myDATA errors 202, 207, 208 and 312, and safe retries.
- [Card / POS](https://developers.novusconceptus.com/faq/card-payments/): Card and IRIS payments through a POS with the Novus e-invoicing API: NSP integration, testing without a terminal, provider signature, failed payments, refunds.
- [Food service](https://developers.novusconceptus.com/faq/food-service/): FAQ on food service order slips (8.6) with the Novus e-invoicing API for Greece and myDATA: closing tables, MARK 0, GetOpenTables, GetOpenOrdersForTable.
- [Goods movement](https://developers.novusconceptus.com/faq/delivery/): FAQ on delivery notes and digital goods movement with the Novus e-invoicing API for Greece: 9.x and 10.x types, isDeliveryNote, movePurpose, myDATA 2.0.2.
- [B2G (public sector)](https://developers.novusconceptus.com/faq/b2g/): B2G e-invoicing FAQ for Greek public bodies with the Novus API: Contracting Authority code, budget type, ΑΔΑ, Ενάριθμος, CPV codes and common B2G errors.
- [General](https://developers.novusconceptus.com/faq/general/): General FAQ on the Novus e-invoicing API for Greece, covering rate limits, myDATA changes, reconciliation with AADE, VAT number lookups and mandatory scope.

## Changelog

- [Changelog](https://developers.novusconceptus.com/changelog/): Changelog of the Novus e-invoicing API for Greece, month by month: every AADE myDATA update up to version 2.0.2, implemented in the Provider API.

## Optional

- [Greek version of this documentation, full text](https://developers.novusconceptus.com/el/llms-full.txt)