What renters under 25 should expect to pay extra.
Many rental companies apply a young-driver surcharge for renters under 25, and some don't rent to drivers under 21 at all, particularly for larger or higher-value vehicles. This surcharge varies significantly by country and company, so it's worth checking the specific policy before booking rather than assuming a flat rate applies everywhere.
A few companies waive this fee for certain loyalty program members or specific card types, so it's worth asking directly if the surcharge seems avoidable.