The telecom operator cannot offer you a subscription for more than 24 months.
If you are a microenterprise (maximum 9 employees), a small enterprise (yearly average of maximum 49 employees), a non-profit micro-organisation (non-profit organisation or foundation with a yearly average of maximum 9 employees), or a small non-profit organisation (non-profit organisation, NGO or foundation with a yearly average of maximum 49 employees), you can explicitly and freely accept to exceed this period at the time of conclusion of the contract.