Kastle Systems' Back to Work Barometer has emerged as the nation’s official office occupancy indicator, but real estate players in New York say it doesn’t paint an accurate picture of the city's office activity.

Kastle tracks security card swipes at buildings in the 10 biggest cities across the country, but it doesn't track buildings owned or managed by SL Green, Vornado, Tishman Speyer, Rudin Management, Silverstein Properties, Brookfield, Boston Properties, Related or Rockefeller Group, the New York Post reports.

Combined, those landlords own tens of millions of square feet and many of the newest trophy towers in the city, such as Hudson Yards, One Vanderbilt, the World Trade Center and Manhattan West.

Kastle fully tracks only one of the city’s 10 biggest portfolios, the Post reports. And it doesn't track six of the towers owned and occupied by financial services users, like JP Morgan Chase’s headquarters at 383 Madison Ave.

“It is reporting data from a mix of A and B properties,” CBRE Tri-State CEO Mary Ann Tighe told the Post. “We know that better buildings have significantly higher occupancy rates, and any building serving the financial service industry has strong in-person attendance. Kastle can’t be considered a definitive source for Manhattan office occupancy.”

The Partnership for New York City's return-to-work survey shows 50% average Manhattan weekly occupancy. Kastle’s latest report shows occupancy of 47.8% compared to pre-pandemic levels, a significant jump from 43.8% the previous week. A representative for Kastle told the Post that it is confident its barometer reflects return-to-work trends accurately.

Tensions have been brewing through most of the year as corporate and political leaders have been pushing workers to come back to their offices more often, but many workers have refused. Labor Day this year didn't bring a large jump in office occupancy, but companies are increasingly mandating workplace returns — which many in real estate expect will push occupancy up further by the end of the year.

“It's not a five-day workweek anymore … [but] people need to be in offices, people need this interaction,” Silverstein Properties CEO Marty Burger said on Bisnow’s podcast last month.

He predicted the company’s buildings will be 70%-80% occupied by the end of the year.

Kastle's tracker hit a new high nationwide last week, measuring 49% of pre-pandemic occupancy. New York had the biggest week-to-week jump, climbing from 43.8% to 47.8%, but every city tracked saw an uptick of at least half a percentage point.