Uploader's Comments

Thanks to Robert Lamb, the leftmost part of the building is the police station and the rest of the building is indeed offices and is called Kirkdale House. The businesses occupying the offices are the Outer Northeast London branch of the NHS, G2 Speech UK, The Instructor College, Capital Finance One and Equifinance. I think there's also a medical recruitment agency there as well called Urban Medical, as you can see a large poster advertising it from the platforms at Leytonstone tube station and the bus stands.