The World Data Centre for Geomagnetism, Mumbai is the part of the Indian Institute of Geomagnetism, an autonomous research institute under the Department of Science and Technology, Govt. of India. The Centre is situated in the campus of old Colaba Magnetic Observatory, Bombay (Geographic lat: 180 53' 36" N long:720 48' 54" E, Dipole lat 10.03N long 145.97) which was operational from 1841 to 1906. Continuity of the magnetic observation is maintained with the commissioning of Alibag magnetic observatory. Colaba - Alibag combined series makes the magnetic data for a period of more than 150 years. This Centre has collected a comprehensive set of analog and digital geomagnetic data as well as indices of geomagnetic activity supplied from a worldwide network of magnetic observatories. The Data Services at the WDC are available for scientific use without restrictions.