C-DRONE GUIDE · 9 JUNE 2026
Drones under vs over 250 g: what really changes
The success of the DJI Mini and other 249 g drones rests on a promise: "under 250 g, no constraints". Regulatory reality is more nuanced: the 250-gram threshold significantly lightens the obligations, but exempts you neither from registration, nor from airspace rules, nor from privacy law. Here is what actually changes at each threshold in 2026.
What the 250 g threshold really allows
A class C0 or privately built drone of less than 250 g (battery included) flies in subcategory A1, the most permissive of the open category. Concretely: no mandatory training — no A1/A3 exam to sit, though the DGAC strongly recommends it —, the ability to fly close to isolated people and occasionally over them (avoiding it as much as possible), and no minimum pilot age for an aircraft covered by the toy directive. The maximum height remains 120 m, as for everyone.
Another notable relief: under 800 g, no individual aircraft registration and no French electronic conspicuity requirement. And for flights around the European Union while travelling, C0 is the simplest class to take abroad: the same A1 rules everywhere, with no extra formality in the visited country beyond the operator registration, which is valid across the whole EU. That simplicity is what made the 249 g segment nearly half of all camera-drone sales in Europe.
What remains mandatory even under 250 g
First point, massively overlooked: operator registration on AlphaTango is mandatory as soon as the drone carries a camera (toys excepted) — hence for every DJI Mini, Autel Nano and equivalent. The FRA number must be marked on the aircraft and entered in the Remote ID. Second point: all airspace rules apply regardless of weight — prohibited zones on the Géoportail map, airport CTRs, maximum height, the ban on leisure flight over public space in built-up areas, the ban on overflying assemblies of people. A 249 g Mini above a Christmas market is just as illegal as a 2 kg drone.
Third point: ground law is weight-blind. Privacy (article 226-1 of the criminal code), image rights, GDPR for professional uses, neighbourhood nuisance: everything applies identically. Finally, professional use of a sub-250 g drone does not bypass the operator framework: mandatory aviation liability insurance (EC regulation 785/2004), préfecture notification to fly over urban public space — possible in the open category for professionals since 1 January 2026, with no overflight of people and daytime only. Weight never replaces the operating framework.
The other thresholds that matter: 800 g, 900 g, 4 kg, 25 kg
The regulation stacks several weight thresholds worth locating precisely. 800 g: the French threshold triggering individual aircraft registration on AlphaTango and electronic conspicuity. 900 g: the class C1 limit, the last class allowed to fly in A1 (exceptional overflight of isolated people). 4 kg: the class C2 and subcategory A2 limit — flight at 30 m from third parties with the A2 certificate. 25 kg: the ceiling of the entire open category (A3 only above 4 kg); beyond it you necessarily enter the specific or certified category. 20 kg: the threshold above which even leisure model aircraft must be insured under regulation 785/2004 — professional use, for its part, requires aviation liability insurance whatever the weight (around €900,000 minimum cover).
| Threshold | Obligation triggered |
|---|---|
| ≥ 250 g (or camera) | AlphaTango operator registration, A1/A3 training |
| ≥ 800 g | Aircraft registration + electronic conspicuity (France) |
| > 900 g | End of A1: fly in A2 (30 m from people) or A3 (far from everything) |
| > 4 kg | End of A2: A3 only within the open category |
| Professional use (any weight) or ≥ 20 kg | Mandatory aviation liability insurance, ~€900k minimum (EC regulation 785/2004) |
| > 25 kg | Exit from the open category: specific or certified |
Sub-250 g drones for professional use: strengths and limits
The 249 g drone has become a genuine auxiliary professional tool: quick roof diagnostics, rural real-estate photos, scouting before heavier missions. Its regulatory strengths are real — A1 flight near people, no certificate required for the occasional pilot, quiet operation. Its limits are just as real: a smaller sensor and wind sensitivity that cap quality in difficult conditions, no C5 class version which rules it out of STS-01 over urban public space, and reduced endurance that stretches coverage missions.
The winning setup seen among French operators: a sub-250 g aircraft for close-proximity flights and sensitive environments, a 900 g-4 kg C2 for routine production in A2, and a heavy machine for photogrammetry and technical inspection. For the client, a "small" drone in the provider's fleet is rather a good sign: it shows a proportionate approach to risk, where the tool adapts to the site rather than the other way round.
Should you buy under or over 250 g?
For a beginner hobbyist, the answer is almost always: under 250 g. The initial outlay is lower (€350 to €1,100 depending on the range in 2026), the obligations boil down to free registration and zone compliance, and skills can grow without administrative risk. Sitting the free A1/A3 exam nonetheless remains the best first reflex: it prevents the zone mistakes that make up most beginner offences.
For regular professional use, the choice follows the missions: image quality, wind stability, sensors (zoom, thermal, LiDAR) and STS scenario eligibility point towards classes C2, C3 and C5, with the matching training and insurance. The economics are quickly settled: the regulatory cost difference between a 249 g aircraft and a C2 (exams, registrations, insurance) is under €600 in the first year — negligible against the gap in deliverable value. Weight is a compliance parameter, never a business strategy.