A total of 1.4 million people live in the informal settlements of the West Bengal city of Kolkata, which represents around 30% of the urban population. Up until recently, these residents had no addresses accessible via GPS; GPS would merely guide visitors to the entrance of the slum, without any directions on how to navigate once there. A Dublin-based charity organization, Addressing The Unaddressed, has designed an intervention that is making the slum lanes of Kolkata recognizable to digital navigation maps like Google Maps.

Urban activists at Addressing The Unaddressed have been coding roads using GPS-based technology to give geo-coordinate-based addresses to slum residents making their home in Kolkata. The first round of coding was completed in 2013; Chetla was the first settlement to be mapped, with more than 2,500 houses and buildings numbered. Ever since, the NGO has continued to supply addresses to over 20,000 homes in 13 of Kolkata’s informal settlements. Signs of codes can be seen nailed to doors bordering the slum lanes; each sign is made up of nine letters and numbers painted in white on a blue placard, similar to a car’s license plate.

Official addresses are important markers for development, since an address is considered part of a person’s identity. “If you do not have an address you do not officially exist,” notes UN-Habitat’s Joan Clos. It is estimated that up to four billion people lack such an identity.

With trackable addresses and the digitization of slum lanes, slum residents can now receive postal services without worrying about letters or packages getting lost. To help postal workers navigate the coded address system between the slum lanes, the NGO carried out training sessions with local postal workers. They even placed hand-drawn maps of the slum lanes at the entrance of each settlement marked with residences and their associated codes. The coders have also linked the names of residents above the age of 18 to the affiliated address along with the phone number of the household head.

Besides having access to postal services, Kolkata’s residents can now open bank accounts and apply for biometric governmental identification cards linked to social and health services as well as voting rights and access to ration cards to purchase food at subsidized prices.

“At our current rate of funding, addressing and increased working, and if the funding keeps coming, we should have addressed all 1.4m people who live in the slums of Kolkata addressed by 2026,” their website states. “We will need about bout €350,000 [Rs2.5m / $38,750] to do this. The more funding we raise the quicker we can complete the work.”