When you register as a UAS operator, you receive a string of characters that most pilots copy in full: onto the label, into the drone app, into forms. But that string has two parts, and one of them should never leave the drone.

The rule comes from the EASA material that accompanies Regulation (EU) 2019/947, and it is the same in every EU state, Romania included.

Key points

  • You register as an operator if you fly in the open category with a drone of 250 g or more, with a drone that has a camera (toys excepted), or at any time in the specific category.
  • The operator number has 16 characters and starts with the country code: ROU for Romania.
  • At registration you also receive three secret digits, written after a hyphen.
  • On the drone you display only the number, without those three characters.
  • The full string (number + secret digits) goes only into the drone's Remote ID system.
  • The three characters are shared with no one: not on the label, not in requests, not in forms.

Who has to register

Article 14(5) of Regulation (EU) 2019/947 requires operator registration when you fly:

  • in the open category, a drone of 250 g or more (or one that could transfer more than 80 J to a person on impact);
  • in the open category, a drone with a sensor able to capture personal data — in practice a camera —, unless it is a toy compliant with Directive 2009/48/EC;
  • in the specific category, a drone of any mass.

You register in the state where you live, and in only one (Art. 14(6)); the state may give the registration a validity period, after which you renew it. In Romania, the authority is AACR — the Romanian Civil Aviation Authority. It is the operator that is registered, not each drone: you put the same number on every drone you operate.

What the number looks like

The EASA material (AMC1 to Art. 14(6)) describes the format:

  1. 3 characters — the country code, upper case (ROU, FIN, DEU…);
  2. 12 characters generated at random, lower-case letters and digits;
  3. 1 check character, computed from the 12 above and from the secret digits.

That makes 16 characters. Separately, the state generates 3 secret characters and hands them to you together with the number, after a hyphen.

The official EASA example (GM1 to Art. 14(6)) is:

  • the full string received at registration: FIN87astrdge12k8-xyz
  • the operator number: FIN87astrdge12k8
  • the secret digits: xyz

What you display on the drone

Art. 14(8) requires the operator number to be displayed on every drone for which registration is mandatory. AMC1 to Art. 14(8) specifies that:

  • the drone carries the operator number — without the secret digits;
  • the number must be readable at least when the drone is on the ground, with nothing more than eyeglasses;
  • a QR code may be used;
  • if the drone is too small for a visible mark on the body, a mark inside the battery compartment is acceptable, provided the compartment can be opened.

How to mark the drone in practice

The rule says what must be visible, not how. The options pilots use are:

  • a printed, water-resistant sticker — the simplest;
  • laser engraving on the shell or on a small plate fixed to it;
  • a permanent marker, quick but fading over time.

Pick a flat surface on the main body, visible without taking anything apart. Check the label now and then: a number that can no longer be read no longer meets the requirement.

What you enter in Remote ID

Here, and only here, the full string goes in. AMC1 to Art. 14(8) requires the operator to upload the operator number together with the three secret digits into the drone's electronic identification system, if it has one.

On drones with built-in Remote ID, the field is usually in the manufacturer's app, under the safety or identification settings. Enter the string exactly as you received it, hyphen included, if the app accepts it.

Why you share the secret digits with no one

GM1 to Art. 14(6) states explicitly that the operator should not share with anybody the three secret digits. They exist to stop someone else from uploading your number into their drone.

The operator number is public by design: it is stuck on the drone. Someone who also has the secret digits can program another drone to broadcast in Remote ID that it is you, and that drone's flights would show up as yours.

So those three characters do not belong:

  • on the label;
  • in authorisation requests or notifications to ROMATSA or any other authority;
  • in screenshots, photos of the certificate, or messages in pilot groups.

Where Drone Log comes in

In your Drone Log profile you can enter the operator number exactly as it appears on your certificate — with or without the secret digits. The documents the app generates use only the operator number:

  • the notification and the authorisation request to ROMATSA (Annex 1 and Annex 2);
  • the flight log exports (PDF and CSV).

If you entered the full string, Drone Log cuts the three characters itself before the document leaves. Your profile stays as you wrote it.

Before flying, check the location on the UAS map and the day's restrictions with the flight check. For more on Remote ID and drone classes, see the guide on marking and identification.

What it means for you

Keep your operator certificate to yourself. Copy only the first 16 characters onto the label, enter the full string in the drone app for Remote ID, and never send anyone the three characters after the hyphen.

In short

  • The operator number (16 characters, starts with ROU) is public: you display it on every drone.
  • The secret digits (3 characters, after the hyphen) are private: they only go into Remote ID.
  • The full string does not appear on the label, in requests or in forms.
  • Drone Log uses only the operator number in documents, even if your profile holds the full string.

Frequently asked questions

What are the three characters after the hyphen?

They are the secret digits generated at registration. They protect your operator number: without them, no one can validly load it into another drone.

Do I put the secret digits on the drone too?

No. On the drone you display only the operator number, the first 16 characters. The secret digits go only into the Remote ID system.

Do I have to register every drone separately?

In the open category, no: the operator is registered, and you display the same number on all your drones. Registering the drone itself as an aircraft only applies to drones whose design is subject to certification.

My drone is under 250 g. Do I need to register?

Yes, if it has a camera and is not a toy compliant with Directive 2009/48/EC. Most sub-250 g drones with a camera fall into that case.

What if I have already sent the secret digits to someone?

Ask AACR what your options are and, until you hear back, treat the number as exposed.

Does Drone Log send the secret digits in requests?

No. The generated documents use only the operator number. If your profile holds the full string, the three characters are cut automatically before generation.

Sources: Implementing Regulation (EU) 2019/947, Art. 14; EASA, AMC1 and GM1 to Art. 14(6) and AMC1 to Art. 14(8), ED Decision 2020/022/R (Easy Access Rules for Unmanned Aircraft Systems).

To move from theory to practice, check if you can fly or use the airspace checker. If the zone requires it, generate the approval request.