Please note if it takes place during your vacation
Conference and seminar costs are 100% deductible, provided they enable you to improve or specialize in your business. Ultimately, what counts for the tax authorities is maintaining or increasing your profit (see Is this expense deductible ?).
What can you deduct ? Not only the cost of registering for the seminar, but also related expenses: transport, accommodation, meals (restaurant expenses deductible at 69%) and other on-site expenses. If you are a company, you can use Per Diem packages.
A conference takes place at the same time as a private trip 🏖️ ? Round-trip transportation is 100% deductible (for you only !) and other expenses only for the days of the training.
💡 The controller may reject expenses that he deems unreasonable in relation to the needs of your business. He will be more suspicious when the seminar takes place during your vacation. Be sure to keep all evidence, such as registration, documentation and notes, a photo...