General Terms

Using Opex and registering to it as a Subscriber means that you accept the following terms as they may apply from time to time. All present terms are binding for the users of the website. In case of non-acceptance of a term, the use of app.op-ex.gr is expressly prohibited.

The terms and conditions of use remain available on this page and we advise users / subscribers to read them carefully and to visit / use the pages and / or services of this site only if they fully accept them. Terms are subject to change at any time without notice.

Provided Service

The website app.op-ex.gr (hereinafter the “website”) has been created by the company “OPEX SA”, in order to provide accounting services to registered users of the website, who are active in Greece and have an obligation to comply with the requirement to keep single-entry and double-entry books (categoy B and C books), according to the Greek legislation (hereinafter the “Subscriber”), for a monthly price / subscription.

The use of this website for the exercising of unfair practices is prohibited. It is prohibited to offer to exploit part or all of the services provided on this website.

OPEX SA is not responsible for any interruptions or unavailability of the service due to malfunction of the internet or ISPs or other events beyond its control.

The Subscriber responsibly declares that the data he / she registers during his / her registration (or modifies in the future) and during the use of the website are correct and true. Use of Opex concerns him / her and not third parties (except for the users he / she designates).

The taxpayer must submit the documents by the 10th day of the following month.

Charging and payment of services must be made on the 10th day of the following month, from the month in which the services are provided. In case the payment has not been completed by the 20th day of the aforementioned month and after relevant warnings, there will be an interruption of the upload of documents and accounting and tax services will not be provided. The taxpayer is solely responsible for any tax penalties arising from late payments.

The Subscriber can terminate his subscription immediately and without compensation whenever he/she wishes. Data entered are available for download before the termination of the subscription. After the subscription is terminated, data are deleted. Money paid for the current month on the day of the termination is non-refundable.

After a period of 30 days from the charging date (on the 11th day of the month following the month during which the services are provided), if the payment remains pending, the package will be permanently terminated.

In case the price of the monthly subscription is not paid, the subscription is terminated within a reasonable period of time and after the Subscriber is notified by e-mail about their debt.

The original data remain at the premises of the taxpayer.

OPEX SA reserves the right to terminate the use of Opex by the Subscriber in case it has indications that the rights of third parties are violated.


The entire website is the property of  OPEX SA and is governed by the applicable national, European Union and international intellectual property provisions, and is available to its users strictly for personal use. Any copying, reproduction, republication, sale, transmission, distribution, publication, translation, modification in any other way of the web site’s content, in part or in whole, is expressly prohibited unless with the previous written permission of the company OPEX SA.

All other trademarks, product names which are registered trademarks and intellectual property rights of third parties which appear on the pages of the website belong to their rightful owners and fall within their own sphere of responsibility.

Limitation of Liability

The website is used at the responsibility of the User / Subscriber. OPEX SA makes every effort to ensure the proper functioning of the website and the accuracy of the content contained therein. However, it shall not be liable for any damages incurred in connection with the information, services, content and advertisements contained in the website or retrieved through it, unless due to fraud or gross negligence on the part of OPEX SA. Services offered through external links (hyperlinks) are used exclusively to serve the visitors of the website.

The Subscriber accepts that Opex is provided “AS IS”, without guarantee of suitability for any purpose, uninterrupted availability, absence of errors. It is the Subscriber’s sole responsibility to verify and ensure that Opex meets its needs.

The Subscriber understands and accepts that OPEX SA has made every effort to operate well in accordance with internationally accepted standards, however there is no guarantee of 100% availability (uptime) of servers and applications or absolute protection against malware. OPEX SA is not responsible for any damage caused to the users of the website and which will be related to the operation of the website.


This website may maintain a file of recipients’ email addresses for sending newsletters and other informational or financial messages. This information shall never be disclosed to third parties. If you do not wish to receive newsletters or information material, turn off the option when you register or from the “newsletter” page in your account.

Applicable Law

These terms and conditions are governed by the provisions of Greek Law. The Courts of Athens are designated as the competent courts for the resolution of any dispute arising from these terms.