The Heartland Headquarters downtown Oklahoma City is a seven story, 110,000 square foot office building with mixed use first floor. Located at the intersection of historic Automobile Alley and the Downtown Business District, the size, scale, proportion, and form of the building take cues from both, transitioning from the historic to the modern. Limestone colored brick recall the cast stone of the historic, while large expanses of glass provide a modern light filled space.

The project has received multiple awards, including ULI Oklahoma, and AIA.

Miller continues to be the primary architect for Global Payments, the parent company of Heartland.