When filing your annual tax return in France, you must declare your gross turnover (income) before Malt service fees have been deducted.
Sole traders in France—called auto-entrepreneurs or micro-entrepreneurs—are not allowed to deduct any other expenses (ex: operating or investment costs), as a "standardized deduction" will automatically be processed when you submit your French tax return.
Because Malt service fees are considered an operating expense, they cannot be deducted from your gross turnover as a sole trader.
Remember, the rules pertaining to deductions can vary significantly based on either the kind of business (legal status) you operate or the local rules and regulations stipulated by the country in which you live.
Pro-tip: Do not hesitate to contact your local tax authority or a trusted accountant if you have any questions about how to complete your tax return correctly.
Say, you've invoiced €1,000 but received €880 in your bank account (the amount after Malt service fees have been deducted). Should you declare €1000 or €880 in your tax return?
The answer: You need to declare €1,000, as that's the gross turnover that was invoiced directly to your clients.