You should know that…

(Beta version)

You are obliged to have a Card Payment System (known as "P.O.S.") and declare Business Account(s) if at least one of your Activity Code Numbers, either primary or secondary, is included in the list of Activity Codes defined in a Joint Ministerial Decision of the Ministries of Economy and Development and Finance. You can find all the Activity Codes in the Common Ministerial Decree 45231/2017.
The declaration of your business account(s) is made via the IAPR website here, within one month from commencement of an activity that falls within the Activity Codes included of the list. In case of non-declaration or late declaration of your business account, an administrative fine shall be imposed. You are not obliged to declare a business account, even if you have an Activity Code included in the list, as long as you only deal with payers acting as part of their commercial, business or professional activity.
It is clarified that there is a monetary limit based on which transactions for the sale of goods or provision of services in cash is allowed. Transactions of a value greater than the aforementioned monetary limit shall be paid by the recipients of the goods or services, exclusively by card or other electronic means of payment, such as wire transfer, payment via e-banking or use of an electronic wallet.