Issuance Of A Payment Order On The Basis Of An Electronic Invoice

Electronic invoicing has changed the manner in which invoices and other transaction documents are issued and circulated in commercial transactions and transactions involving self-employed professionals. It has not, however, altered the fundamental procedural requirement that a claim be evidenced in writing in order for an enforceable payment order to be issued. Accordingly, the legal basis giving rise to the claim, the amount of the claim and its acceptance by the debtor must be established by documentary evidence. The critical issue, therefore, is not merely whether there exists a valid electronic invoice bearing a Unique Registration Number (MARK) in myDATA, or whether the invoice has been transmitted to the Independent Authority for Public Revenue (AADE) through a private electronic invoicing service provider. Rather, the documents submitted in support of the application, taken as a whole, must establish that the debtor is bound by the underlying transaction — whether a sale, a contract for work or, more generally, the provision of services — that the relevant contractual performance has in fact been duly rendered, and that the debt is certain and due and payable. This distinction has acquired particular importance following the amendments introduced by Law 5222/2025 in relation to electronic invoicing: the recognition, for tax purposes, of an invoice in electronic form is not equivalent to an acknowledgement of the underlying civil-law debt. The purpose of this article is therefore to clarify which documents are required in practice and under what circumstances an electronic invoice may, either on its own or in conjunction with other evidence, support an application for the issuance of an enforceable payment order.

I. Documentary Evidence as an Independent Procedural Requirement for the Issuance of a Payment Order

Under Articles 623 et seq. of the Greek Code of Civil Procedure, the substantive existence of a monetary claim is not, in itself, sufficient for a payment order to be issued. The documents accompanying the application must establish the legal basis of the debt, the identities of the creditor and the debtor, the amount claimed, and the fact that the claim is certain and due and payable.

Documentary evidence constitutes a specific procedural prerequisite. Accordingly, where such evidence is lacking, the payment order may be set aside following an opposition, even where the claim could have been established in ordinary proceedings by witness testimony or other means of evidence (Supreme Court Judgment No. 1413/2022).

The same judgment also highlights a point of particular practical significance in relation to invoices: an invoice issued by the creditor does not, without more, establish that the recipient assumed the corresponding obligation. Consequently, invoices alone do not necessarily prove the agreement constituting the legal basis of the claim, particularly since they do not necessarily bear the recipient’s signature.

It is, however, permissible for the requisite documentary evidence to consist of a combination of several documents, provided that, when assessed as a whole, those documents establish with sufficient certainty the connection between the debtor and the debt in question.

II. Distinction Between the Authenticity of the Invoice and Acceptance of the Debt

Articles 14 and 15 of Law 4308/2014, as amended by Articles 239–240 of Law 5222/2025, regulate the form of electronic invoices, the authenticity of their origin and the integrity of their content.

Authenticity may be ensured, inter alia, through the use of Electronic Invoicing Service Providers or through AADE’s application for the issuance and transmission of invoices and other transaction documents. These mechanisms provide particularly strong evidence as to the identity of the issuer and the integrity of the invoice’s content.

They do not, however, answer the separate question of whether the recipient accepted the specific debt or whether the conditions giving rise to the claim have been satisfied.

Accordingly, the existence of a MARK, the transmission of an invoice to myDATA, or its issuance through a certified service provider establish the issuance of the invoice and, consequently, the issuer’s tax compliance and the invoice’s general tax audit trail. They do not automatically transform a unilaterally issued invoice into a written declaration attributable to the debtor.

III. Signature of an Electronic Invoice and Its Evidential Value

As a starting point, pursuant to Article 443 of the Greek Code of Civil Procedure, in order for a private document to have the evidential value attributed to it by law, it must bear the handwritten signature of its issuer.

In an electronic environment, the function of a handwritten signature is performed by a qualified electronic signature, which is legally equivalent to a handwritten signature. This rule was originally provided for under Presidential Decree 150/2001 and, following its repeal by Article 108(15) of Law 4727/2020, now derives from Article 25(2) of Regulation (EU) No 910/2014 (eIDAS) and Article 50 of Law 4727/2020.

The issue is particularly important in the context of electronic invoices. The fact that an invoice has been validly issued and transmitted for tax purposes does not automatically mean that it constitutes full documentary evidence of the corresponding civil-law claim for the purposes of Articles 623 et seq. of the Greek Code of Civil Procedure.

Accordingly, where an electronic invoice bears neither a handwritten nor a qualified electronic signature and, in particular, where it has been issued unilaterally by the creditor itself, it cannot, as a rule, independently support the issuance of a payment order.

In such circumstances, the invoice must be accompanied by other documents originating from, or accepted by, the debtor, from which the conclusion of the underlying agreement, the existence and amount of the claim and, where applicable, the receipt or due performance of the contractual counter-performance can be established in writing.

In other words, the decisive factor is not merely the “existence” of an electronic invoice, but whether the documentary record as a whole reliably links the invoice to a declaration or conduct attributable to the debtor which has itself been recorded in writing and which enables the claim to be fully established.

IV. When Can an Electronic Invoice Support the Issuance of a Payment Order?

The safest approach is to regard the electronic invoice as one link in a broader chain of documentary evidence.

Supreme Court Judgment No. 1671/2024 is illustrative in this respect. Although the invoice at issue did not bear the signature of the person receiving it, it had been formally registered by the debtor company’s competent accounting department, entered in its accounting records and accompanied by e-mail correspondence and signed certificates confirming the performance and delivery of the relevant work.

The Court of Appeal had held that the absence of a signature on the invoice itself was remedied by the written acceptance evidenced by the remaining documents. The Supreme Court did not overturn that finding. It ultimately set aside the payment order on a different ground, namely that the underlying agreement was invalid as a result of non-compliance with a mandatory constitutive written-form requirement.

Accordingly, depending on the nature of the transaction, documents capable of remedying the evidential deficiency of a unilaterally issued electronic invoice that does not bear handwritten signatures may include:

• a signed contract or purchase order;
• a delivery note or delivery/acceptance protocol;
• e-mail correspondence from a person acting within the scope of his or her authority;
• a written balance confirmation;
• an accounting confirmation issued or accepted by the debtor; or
• a partial payment clearly attributable to the specific invoice.

V. Legal Persons: The Issue of Representation and Authority

Where the debtor is a société anonyme (S.A.), a private company (I.K.E.) or another legal person, it must additionally be established that the relevant declaration of acceptance or receipt is attributable to that legal person.

Supreme Court Judgment No. 1671/2024 draws an important distinction between, on the one hand, an e-mail sent by an ordinary employee of the accounting department — which was insufficient, in itself, to constitute an independent abstract acknowledgement of debt in the absence of evidence of the employee’s authority — and, on the other hand, the body of corporate documentation and accounting entries which ultimately confirmed the transaction.

In practice, therefore, an e-mail stating, for example, “we have received it”, sent by an employee whose authority or capacity has not been established, should not be treated as a reliable equivalent of the signature of the company’s lawful representative.

By contrast, a consistent course of correspondence from the corporate e-mail account of an appropriately authorised officer, a purchase order, formal registration of the invoice, its entry in the company’s accounting records and a partial payment may, when taken together, constitute considerably stronger documentary evidence.

VI. myDATA and the “Non-Rejection” of an Invoice – Not Automatically an Acknowledgement of Debt

Particular caution is required when relying on data recorded in myDATA.

The platform does indeed provide the recipient with the option of rejecting an invoice on the ground of disagreement. This mechanism, however, serves the purposes of tax reporting and the reconciliation of the parties’ electronic accounting records.

It does not follow that the recipient’s failure to act, or its failure to select the rejection option, constitutes, as a matter of general principle, a civil-law acknowledgement of the debt or acceptance that the underlying agreement has been duly performed.

A comparison with the regime governing electronic declarations of lease agreements is instructive. In particular, AADE Governor Decision A.1068/2025 provides that, once a specified period has elapsed without any action being taken by the tenant, a declaration uploaded by the landlord in respect of the commencement of a lease relationship is deemed to have been accepted.

It may therefore be inferred that, where the legislature intends silence to have the legal effect of acceptance, it provides for this expressly.

There is no corresponding provision under which the failure to reject an invoice in myDATA is deemed to constitute acceptance of that invoice.

Consequently, the absence of a rejection may be taken into account as supplementary evidence together with other material, but it would be unsafe to rely upon it as the sole basis for establishing acceptance of the debt in payment-order proceedings.

VII. The Importance of the Legal Basis Giving Rise to the Debt: The Nature of the Underlying Agreement

The documentary evidence required will vary depending on the legal basis giving rise to the debt, namely the particular type of transaction or agreement from which the debt arose.

In a sale of goods, for example, the purchase order or agreement and written evidence of delivery or receipt will be of particular importance.

In the case of services, the documentary record must establish the connection between the invoice, the services agreed upon and the actual performance of those services.

This is particularly significant in relation to a contract for work, under which remuneration is, as a general rule, linked to delivery of the completed work pursuant to Article 694 of the Greek Civil Code. The mere existence of an invoice issued unilaterally by the contractor does not, without further evidence, establish that the work was duly completed and delivered.

Where performance is disputed, a written acceptance document, certification, e-mail confirming acceptance or equivalent documentary evidence originating from the customer will be required.

An even stricter approach applies where the agreement itself is subject, by law or under a specific regulatory framework, to a mandatory constitutive written-form requirement.

VIII. Conclusions

Electronic invoicing does not displace the principle of documentary evidence, nor does it transform myDATA into a mechanism for the automatic creation of enforceable titles.

An application for the issuance of a payment order must be supported by a complete documentary record establishing not only the issuance of the electronic invoice, but also the debtor’s acceptance of the underlying obligation.

In particular, it is advisable, to the extent possible, for the supporting documentation to include cumulatively: i) the agreement, purchase order or other document evidencing the parties’ agreement and the legal basis of the claim; ii) the electronic invoice, together with the relevant issuance and transmission details; iii) written evidence of delivery of the goods or due performance of the services or work; iv) a document or corporate act attributable to the debtor confirming receipt, accounting recognition, the outstanding balance or a partial payment; and v) clear evidence that the claim is due and payable and, where the debtor is a legal person, evidence of the authority of the person making the relevant declaration.

Accordingly, where the supporting documentation is limited to a unilaterally issued electronic invoice and a myDATA printout, without any document originating from the debtor itself, there is a material risk that the payment order may subsequently be set aside following an opposition.

Conversely, where the invoice — insofar as it does not bear the handwritten signatures of the issuer and the recipient — forms part of a complete documentary chain comprising the order, performance, delivery or acceptance and accounting acknowledgement of the transaction, its electronic form does not, in itself, constitute an obstacle to the issuance of a payment order.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.