The House is updating its phone system to make it easier for Capitol Police to track down threatening calls to congressional offices, Axios has learned.

Why it matters: After dropping from their historic 2021 high, threats against lawmakers ticked back up last year and remain at vastly higher levels than the pre-Trump years, according to Capitol Police data.

• Lawmakers have frequently described an environment of heightened insecurity in the wake of the Jan. 6 attack.
• Politico first reported on the updated phone system.

Driving the news: In a notice to congressional offices on Monday, the House Administration Committee said the Capitol's switchboard system will be updated to identify the phone numbers of callers it connects to offices.

• "These changes will greatly enhance the U.S. Capitol Police's ... ability to identify and investigate individuals who make threatening or harassing calls to Member offices," wrote Reps. Bryan Steil (R-Wis.) and Joe Morelle (D-N.Y.), the panel's chair and ranking member.
• The data will not be available for callers who deliberately block their numbers, they said, but the change will make it possible to "track down these 'no caller ID' callers much quicker than previously."
• Morelle and Steil said the update will also make it easier for offices to follow up with constituents.

Between the lines: "The worst calls are nearly always through the switchboard," one congressional staffer told Axios.

• Threats to members of Congress have been a major problem in recent years amid an increase in partisan tensions and inflammatory rhetoric.
• Just last month, offices were bombarded with calls – including threats of violence – against a bill to force a sale of the social media app TikTok.

The bottom line: "Taken together, these technological and systemic upgrades will enhance security for Members and staff and improve constituent services by allowing staff to better track and respond to constituent calls," Morelle and Steil said.

Editor's note: This story has been updated with additional context.