The U.S. government will launch a website for drone registration Dec. 21, charging $5 for a certificate that will last three years. The system is a response to safety concerns triggered by drone sightings near airports, plus the thousands of drones that are expected to be given as gifts this holiday season.

Only drones weighing between 0.55 of a pound and 55 pounds need to register, which covers the most popular consumer models such as the DJI Phantom. Drones under 0.55 of a pound are so light as to be thought not a safety hazard. Drones that weigh more than 55 pounds have to go through aircraft registration.

“While this is one step we’re taking, it is not the only step that the government is taking or will take in the future when it comes to the safe integration of these technologies,” said Department of Transportation Secretary Anthony Foxx in a briefing Monday morning. “We reserve the right to ratchet up or down depending on circumstances.”

Anyone who bought a drone before Dec. 21 must register by Feb. 19. Those purchasing drones after Dec. 21 must register before their first flight outdoors. Failure to register will result in penalties, officials said. They warn of thousands of dollars in penalties and even jail time in egregious circumstances.

Some observers have questioned the legality of the registration system. Eli Dourado, director of the technology policy program at George Mason’s Mercatus Center, believes the rule would be overturned if challenged in court, given how the government rushed the rule-making process, meaning less chance for public comments.

“It would be pretty straightforward for some interested party to go to court and just say, ‘Hey, they’ve had several years to do this but they haven’t,'” Dourado said. “Does it make sense to have an emergency rule-making?”

The Academy of Model Aeronautics expressed disappointment with the registration process, calling it an undue burden for its members who have flown model aircraft for decades.

But government officials are moving forward, seeing this as an opportunity to educate Americans about drone flight, and make the airspace safer.

“Thousands upon thousands of brand new users are starting to fly. And while we’re confident that the vast majority of these people care about safety and want to operate safely, the reality is that most have little to no aviation experiences,” said FAA deputy administrator Michael Whitaker.

Last month an FAA task force of drone manufacturers, pilots, retailers and aviation experts made recommendations for what a system should look like. One major distinction between what they recommended and what the FAA has enforced is the $5 fee. The task force recommended free registration, concerned that a fee would deter users from registering.

“Is it perfect? No. This is the first step,” said Brandon Torres Declet, chief executive of the drone operator Measure, and a member of the task force. “It will change over time and hopefully become even easier to use.”

The registration website will collect the drone owner’s name, physical address and email address. A credit card number will be used to verify the individual and pay the fee. Registration will need to be renewed every three years.

If a used drone is sold, then the new owner will be required to register it. The FAA says the website will have the capability to let an owner de-register if they’re selling their drone or giving it to a friend. An individual must be 13 to register. For children with drones, a parent can register.

The registration site will be linked from the FAA’s website. Those who register within the next 30 days will get their registration fee refunded, the FAA says.