This tech company abandoned its SF headquarters. Now it's taking over an entire office building

For years, San Francisco's office landlords watched tech tenants shrink their footprints, embrace remote work and walk away from long-term leases. Now, one of the companies that once embodied that shift is betting in the opposite direction: Brex, which abandoned its traditional headquarters model during the pandemic, is taking an entire office building off the market for the next decade. 

In a lease signed earlier this month, Brex expanded its presence at 270 Brannan St., taking the entire 200,000-square-foot building. The deal, which was negotiated by JLL's Charlie Hanafin, Chris Roeder and Jak Churton on behalf of landlord Mitsui Fudosan America,  builds on the company's earlier office comeback. After giving up its Financial District headquarters in 2021 and embracing a remote-first approach - with its founders even relocating to Los Angeles - Brex returned to San Francisco in 2025 with a roughly 100,000-square-foot lease at the same property. At the time, some 500 employees were projected to be based in the building. 

Brex's recently expanded commitment gives the company, acquired by Capital One in April, more than three times the space it occupied when it pulled out, and for years to come. 

It's a striking turn for a business built around flexibility and financial efficiency. The fintech operator began as a corporate card provider for venture-backed startups and has since expanded into a broader financial platform for managing expenses, payments and other business operations. The company built its reputation helping startups move quickly and is now making one of the most permanent commitments a business can make: a nearly 10-year bet on a physical workplace. 

The timing of Brex's growing footprint also comes as the company enters a new chapter following its acquisition. The deal gave Brex the backing of a major financial institution while allowing it to continue operating as a standalone business. That development may give the company more room to make long-term investments - including in its workplace strategy.

Ben Gammell, Brex's president, said the company sees the San Francisco lease as part of that next phase.

"San Francisco is Brex's home, and we're excited to be here as we enter our next chapter," Gammell said in a statement to the Chronicle. "We look at the momentum building around AI and see a city entering its best years yet, and we're planting ourselves right in the middle of that. As part of Capital One, Brex has the flexibility to think longer-term and the privilege of investing with real conviction in our products, in our team, and, now, in a location that reflects the company we're becoming."

Brex's bet is still notable, given that office vacancy is still at a historic high in San Francisco, but it is becoming less of a one-off as tech companies begin making larger commitments to the city's office buildings. After years of tenant departures, downsizing and uncertainty, some firms are beginning to move from cutting offices to again choosing them - particularly those tied to artificial intelligence - seeking spaces that can support collaboration, recruiting and growth in a post-pandemic era. 

According to real estate firm CBRE, San Francisco recorded its seventh consecutive quarter of positive net absorption in the second quarter of 2026, meaning that more square feet of occupancy were gained than lost during the quarter. The brokerage reported this month that vacancy in downtown has dropped from a high of nearly 37% in the third quarter of 2024 to 29.2% in the first half of this year.

Expanding AI startups contributed nearly 1 million square feet of net absorption in the second quarter, while leasing activity totaled nearly 3 million square feet.

Demand from tenants in the market for office space "surged" to a record high of 8.9 million square feet, the firm reported, with "40% of this total expected to be for expansion space." 

The recovery, however, has concentrated in certain parts of the market, and in certain buildings: AI companies have driven much of the recent leasing activity in neighborhoods like Mission Bay and China Basin, which recorded the lowest office vacancy of any submarket at 17%, while the Yerba Buena area recorded the highest vacancy at 62.7%, per CBRE. 

Class A buildings - modern properties in prime locations with views - accounted for 77% of leasing activity in the second quarter, with companies gravitating toward newer or upgraded offices with amenities and access to transit. Brex's office in a relatively modern, 2016-era creative office building in the South Beach neighborhood, which is located just north of Mission Bay where AI pioneer OpenAI has laid roots, appears to largely fit the bill. 

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