Streetdirectory.com Inland Revenue Authority Of Singapore (IRAS) is in Thomson, Singapore. Located in the outskirts of the Central Business District, Thomson is named after architect and surveyor in the colonial period. Today, the district contains a mix of offices, private residences and shopping centres. Most of these amenities are concentrated at the south of Thomson - those thinking of staying at serviced apartments like Newton Suites can easily shop at Goldhill Plaza or United Square, or do business at Revenue House. Also, medical facilities are easily available in Thomson, in the reputable Thomson Medical Centre.