This is the first paper to identify, using a field experiment, the effects of intense one-on-one assistance by a professional social worker on the take-up of social benefits within a population of deeply disadvantaged informal workers. A municipal program exists that entails providing these disadvantaged informal workers with a formal permit to work on the streets and make contributions to the retirement pension system. We randomly assign one-on-one assistance to these informal workers, and within this treatment group, we randomly assign money to cover the cost of the documents required by the municipality. We find that a worker who receives one-on-one assistance is three times more likely to receive the municipal permit than a worker in the control group. We also find that a worker who receives both one-on-one assistance and cost coverage is four times more likely to obtain the municipal permit. Providing information alone does not have an impact. The program has no spillover effect on the take-up of other national support programs that are not targeted by the one-on-one assistance intervention. These findings identify possible strategies to remove barriers to increase the take-up of social benefits within deeply vulnerable populations.