UNDATED (WOWO): Drones were a popular gift this holiday season, but did you know you need to register it first?

About 400,000 drones were expected to be sold during the holidays this year. The popular toy, or professional camera mount if you're a photographer, can also cause havoc in the skies. 

The Federal Aviation Administration starts requiring the registration of your drone before it takes its first flight on Monday. 

Already have a drone? It needs to be registered within 60 days. 

You can register your drone for three years for $5 online, with that $5 refunded if you register before the last week of January.  

To register your drone, click here.