Can I get a class label for a drone that I have already bought?

In short: Yes. However, there are not a lot of drones available on the market for which this is likely. It is possible for a manufacturer to issue a class label later as it formally is a declaration of conformity: No individual drones are tested but the manufacturer declares, with the backing of a laboratory, that they are adhering to all rules that are relevant for the issuing of the certificate.

This means that for your drone to receive a class label, the manufacturer must include all features and adhere to all restrictions for a specific class and then release the drone into the market without waiting for a laboratory to make all necessary tests. Only if the laboratory tests result in a complete success and no hardware-side changes are necessary, software changes can be delivered by update, then a drone series may receive a class label retroactively.

The only example that is currently on the market is the DJI Mavic 3 (buy one on Amazon). If you already have one, but without the label, you can order a label from DJI and retroactively apply it to your drone.

Furthermore, the Mavic Mini 3 (buy on Amazon) should be prepared to receive a C0 class label, however no declaration of conformity has been issued yet and we cannot guarantee that it will receive one.