General¶

Q: Are there rate limits on the number of API calls?

For now, there is a limit only on the Onboarding API: 60 calls per minute per key, with the X-RateLimit-Remaining header. Above that, it returns 429 RATE_LIMITED with Retry-After. On the Provider API, the certified e-invoicing provider sets no limit, but calls such as RequestTransmittedDocs also depend on AADE (the Greek tax authority), so do not poll more often than you need to. See: Onboarding API: endpoints

Q: I found a document that shows as transmitted in myDATA but is missing from the Provider's documents. What do I do?

To reconcile, use RequestTransmittedDocs with the issuer VAT number (ΑΦΜ) and a date range, or with invoiceMark/uid, to see what the Provider has recorded. To investigate a mismatch, Novus needs the invoiceUid, or the request and response JSON of that specific submission. This is why your application should keep the request and response of every submission, together with the MARK, UID, Authentication Code and invoiceUrl. See: Other calls

Limits, archiving, legal framework.

Are there rate limits on the number of API calls?

For now, there is a limit only on the Onboarding API: 60 calls per minute per key, with the X-RateLimit-Remaining header. Above that, it returns 429 RATE_LIMITED with Retry-After. On the Provider API, the certified e-invoicing provider sets no limit, but calls such as RequestTransmittedDocs also depend on AADE (the Greek tax authority), so do not poll more often than you need to.

See: Onboarding API: endpoints

How do I stay informed about myDATA changes and new versions of the API documentation?

We announce the changes that affect you (new myDATA versions, new fields, API changes) on the Changelog page of the documentation, before they take effect. Novus Conceptus, as a certified Provider, adapts its infrastructure to AADE's changes. For official announcements and specifications, the source is the myDATA section of the AADE website.

See: Changelog

I found a document that shows as transmitted in myDATA but is missing from the Provider's documents. What do I do?

To reconcile, use RequestTransmittedDocs with the issuer VAT number (ΑΦΜ) and a date range, or with invoiceMark/uid, to see what the Provider has recorded. To investigate a mismatch, Novus needs the invoiceUid, or the request and response JSON of that specific submission. This is why your application should keep the request and response of every submission, together with the MARK, UID, Authentication Code and invoiceUrl.

See: Other calls

Does the API offer a lookup of business details (name, address) by VAT number?

No. The Provider API has no lookup of business name or address by VAT number. Your application sends the recipient's details. For lookups, AADE offers the "Αναζήτηση Βασικών Στοιχείων Μητρώου" service (basic registry data lookup), with your own access credentials.

Can I send only some documents through the Provider (e.g. only invoices) and transmit the rest another way?

Technically, the Provider transmits only the documents your application sends to SendInvoices. Anything you do not send does not go through it. However, the law, not the Provider, defines which documents must be issued through a Provider: from 1 October 2026 the obligation also covers the last group of businesses for B2B and B2G invoices, which are issued either through a Provider or through AADE's free applications. For each client, confirm with their accountant which documents can stay outside the Provider.