Moving from sole-trader (micro) status to a company is a major strategic step. When to make the leap? Generally when your revenue exceeds €60,000 net (after material costs) or when you want to hire. The €77,700 micro threshold (services) approaches fast once business takes off. SARL or SAS? The SARL is often preferable for a solo tradesperson: lower social charges (around 40% vs 65-80% for a SAS), personal asset protection, stronger credibility with clients and suppliers. The tax impact: under the micro regime, you are taxed on revenue. As a company, on actual profit. If your costs exceed 30% of revenue, the company becomes advantageous. The steps: drafting the articles, depositing the capital (€1 minimum but €5,000 recommended), registration, transferring the client base. Allow €1,500 to €3,000 in set-up costs. Our advice: get support from an accountant specialised in construction. Choices made at creation (VAT regime, IS/IR option, salary vs dividends) have a major long-term impact on your tax position.