PROFESSIONAL INCOME: SINGLE-ENTRY OR DOUBLE-ENTRY ACCOUNTING?
Traders and liberal professions (doctors, lawyers, etc.) must keep "double-entry" accounts as soon as their annual turnover exceeds €100,000.
Double-entry accounting is the accounting technique used in companies and implies that each transaction is recorded for the same amount simultaneously in two accounts: a credit account which is normally that of the resource of the transaction) and a debit account (which is that of the use of the transaction)1.
Thus, for example, the receipt of an invoice is simultaneously credited to the customer account (the resource of the sum of money) and debited from the bank account (the use of the sum of money). The payment of an invoice to a supplier is credited to the bank account (the source of the money) and debited from the supplier's account (the use of the money).
Traders and the liberal professions (doctors, lawyers, etc.) who generate a turnover of less than €100,000 per year have the possibility of keeping simplified accounts, i.e. by recording their profit simply by the difference between the arithmetic sum of their income and the arithmetic sum of their expenditure.
In summary:
1) Article 7 of the Act of 23 December 2016 on the implementation of the tax reform, Mémorial A no. 274 of 27th December 2016